diff.con commit git svn: avoid uninitialized var in 'reset' (70ee0b7)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33
  34static char diff_colors[][COLOR_MAXLEN] = {
  35        GIT_COLOR_RESET,
  36        GIT_COLOR_NORMAL,       /* PLAIN */
  37        GIT_COLOR_BOLD,         /* METAINFO */
  38        GIT_COLOR_CYAN,         /* FRAGINFO */
  39        GIT_COLOR_RED,          /* OLD */
  40        GIT_COLOR_GREEN,        /* NEW */
  41        GIT_COLOR_YELLOW,       /* COMMIT */
  42        GIT_COLOR_BG_RED,       /* WHITESPACE */
  43        GIT_COLOR_NORMAL,       /* FUNCINFO */
  44};
  45
  46static void diff_filespec_load_driver(struct diff_filespec *one);
  47static size_t fill_textconv(struct userdiff_driver *driver,
  48                            struct diff_filespec *df, char **outbuf);
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int git_config_rename(const char *var, const char *value)
  72{
  73        if (!value)
  74                return DIFF_DETECT_RENAME;
  75        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  76                return  DIFF_DETECT_COPY;
  77        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  78}
  79
  80/*
  81 * These are to give UI layer defaults.
  82 * The core-level commands such as git-diff-files should
  83 * never be affected by the setting of diff.renames
  84 * the user happens to have in the configuration file.
  85 */
  86int git_diff_ui_config(const char *var, const char *value, void *cb)
  87{
  88        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  89                diff_use_color_default = git_config_colorbool(var, value, -1);
  90                return 0;
  91        }
  92        if (!strcmp(var, "diff.renames")) {
  93                diff_detect_rename_default = git_config_rename(var, value);
  94                return 0;
  95        }
  96        if (!strcmp(var, "diff.autorefreshindex")) {
  97                diff_auto_refresh_index = git_config_bool(var, value);
  98                return 0;
  99        }
 100        if (!strcmp(var, "diff.mnemonicprefix")) {
 101                diff_mnemonic_prefix = git_config_bool(var, value);
 102                return 0;
 103        }
 104        if (!strcmp(var, "diff.external"))
 105                return git_config_string(&external_diff_cmd_cfg, var, value);
 106        if (!strcmp(var, "diff.wordregex"))
 107                return git_config_string(&diff_word_regex_cfg, var, value);
 108
 109        return git_diff_basic_config(var, value, cb);
 110}
 111
 112int git_diff_basic_config(const char *var, const char *value, void *cb)
 113{
 114        if (!strcmp(var, "diff.renamelimit")) {
 115                diff_rename_limit_default = git_config_int(var, value);
 116                return 0;
 117        }
 118
 119        switch (userdiff_config(var, value)) {
 120                case 0: break;
 121                case -1: return -1;
 122                default: return 0;
 123        }
 124
 125        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 126                int slot = parse_diff_color_slot(var, 11);
 127                if (slot < 0)
 128                        return 0;
 129                if (!value)
 130                        return config_error_nonbool(var);
 131                color_parse(value, var, diff_colors[slot]);
 132                return 0;
 133        }
 134
 135        /* like GNU diff's --suppress-blank-empty option  */
 136        if (!strcmp(var, "diff.suppressblankempty") ||
 137                        /* for backwards compatibility */
 138                        !strcmp(var, "diff.suppress-blank-empty")) {
 139                diff_suppress_blank_empty = git_config_bool(var, value);
 140                return 0;
 141        }
 142
 143        return git_color_default_config(var, value, cb);
 144}
 145
 146static char *quote_two(const char *one, const char *two)
 147{
 148        int need_one = quote_c_style(one, NULL, NULL, 1);
 149        int need_two = quote_c_style(two, NULL, NULL, 1);
 150        struct strbuf res = STRBUF_INIT;
 151
 152        if (need_one + need_two) {
 153                strbuf_addch(&res, '"');
 154                quote_c_style(one, &res, NULL, 1);
 155                quote_c_style(two, &res, NULL, 1);
 156                strbuf_addch(&res, '"');
 157        } else {
 158                strbuf_addstr(&res, one);
 159                strbuf_addstr(&res, two);
 160        }
 161        return strbuf_detach(&res, NULL);
 162}
 163
 164static const char *external_diff(void)
 165{
 166        static const char *external_diff_cmd = NULL;
 167        static int done_preparing = 0;
 168
 169        if (done_preparing)
 170                return external_diff_cmd;
 171        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 172        if (!external_diff_cmd)
 173                external_diff_cmd = external_diff_cmd_cfg;
 174        done_preparing = 1;
 175        return external_diff_cmd;
 176}
 177
 178static struct diff_tempfile {
 179        const char *name; /* filename external diff should read from */
 180        char hex[41];
 181        char mode[10];
 182        char tmp_path[PATH_MAX];
 183} diff_temp[2];
 184
 185typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 186
 187struct emit_callback {
 188        int color_diff;
 189        unsigned ws_rule;
 190        int blank_at_eof_in_preimage;
 191        int blank_at_eof_in_postimage;
 192        int lno_in_preimage;
 193        int lno_in_postimage;
 194        sane_truncate_fn truncate;
 195        const char **label_path;
 196        struct diff_words_data *diff_words;
 197        int *found_changesp;
 198        FILE *file;
 199        struct strbuf *header;
 200};
 201
 202static int count_lines(const char *data, int size)
 203{
 204        int count, ch, completely_empty = 1, nl_just_seen = 0;
 205        count = 0;
 206        while (0 < size--) {
 207                ch = *data++;
 208                if (ch == '\n') {
 209                        count++;
 210                        nl_just_seen = 1;
 211                        completely_empty = 0;
 212                }
 213                else {
 214                        nl_just_seen = 0;
 215                        completely_empty = 0;
 216                }
 217        }
 218        if (completely_empty)
 219                return 0;
 220        if (!nl_just_seen)
 221                count++; /* no trailing newline */
 222        return count;
 223}
 224
 225static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 226{
 227        if (!DIFF_FILE_VALID(one)) {
 228                mf->ptr = (char *)""; /* does not matter */
 229                mf->size = 0;
 230                return 0;
 231        }
 232        else if (diff_populate_filespec(one, 0))
 233                return -1;
 234
 235        mf->ptr = one->data;
 236        mf->size = one->size;
 237        return 0;
 238}
 239
 240static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 241{
 242        char *ptr = mf->ptr;
 243        long size = mf->size;
 244        int cnt = 0;
 245
 246        if (!size)
 247                return cnt;
 248        ptr += size - 1; /* pointing at the very end */
 249        if (*ptr != '\n')
 250                ; /* incomplete line */
 251        else
 252                ptr--; /* skip the last LF */
 253        while (mf->ptr < ptr) {
 254                char *prev_eol;
 255                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 256                        if (*prev_eol == '\n')
 257                                break;
 258                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 259                        break;
 260                cnt++;
 261                ptr = prev_eol - 1;
 262        }
 263        return cnt;
 264}
 265
 266static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 267                               struct emit_callback *ecbdata)
 268{
 269        int l1, l2, at;
 270        unsigned ws_rule = ecbdata->ws_rule;
 271        l1 = count_trailing_blank(mf1, ws_rule);
 272        l2 = count_trailing_blank(mf2, ws_rule);
 273        if (l2 <= l1) {
 274                ecbdata->blank_at_eof_in_preimage = 0;
 275                ecbdata->blank_at_eof_in_postimage = 0;
 276                return;
 277        }
 278        at = count_lines(mf1->ptr, mf1->size);
 279        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 280
 281        at = count_lines(mf2->ptr, mf2->size);
 282        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 283}
 284
 285static void emit_line_0(FILE *file, const char *set, const char *reset,
 286                        int first, const char *line, int len)
 287{
 288        int has_trailing_newline, has_trailing_carriage_return;
 289        int nofirst;
 290
 291        if (len == 0) {
 292                has_trailing_newline = (first == '\n');
 293                has_trailing_carriage_return = (!has_trailing_newline &&
 294                                                (first == '\r'));
 295                nofirst = has_trailing_newline || has_trailing_carriage_return;
 296        } else {
 297                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 298                if (has_trailing_newline)
 299                        len--;
 300                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 301                if (has_trailing_carriage_return)
 302                        len--;
 303                nofirst = 0;
 304        }
 305
 306        if (len || !nofirst) {
 307                fputs(set, file);
 308                if (!nofirst)
 309                        fputc(first, file);
 310                fwrite(line, len, 1, file);
 311                fputs(reset, file);
 312        }
 313        if (has_trailing_carriage_return)
 314                fputc('\r', file);
 315        if (has_trailing_newline)
 316                fputc('\n', file);
 317}
 318
 319static void emit_line(FILE *file, const char *set, const char *reset,
 320                      const char *line, int len)
 321{
 322        emit_line_0(file, set, reset, line[0], line+1, len-1);
 323}
 324
 325static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 326{
 327        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 328              ecbdata->blank_at_eof_in_preimage &&
 329              ecbdata->blank_at_eof_in_postimage &&
 330              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 331              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 332                return 0;
 333        return ws_blank_line(line, len, ecbdata->ws_rule);
 334}
 335
 336static void emit_add_line(const char *reset,
 337                          struct emit_callback *ecbdata,
 338                          const char *line, int len)
 339{
 340        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 341        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 342
 343        if (!*ws)
 344                emit_line_0(ecbdata->file, set, reset, '+', line, len);
 345        else if (new_blank_line_at_eof(ecbdata, line, len))
 346                /* Blank line at EOF - paint '+' as well */
 347                emit_line_0(ecbdata->file, ws, reset, '+', line, len);
 348        else {
 349                /* Emit just the prefix, then the rest. */
 350                emit_line_0(ecbdata->file, set, reset, '+', "", 0);
 351                ws_check_emit(line, len, ecbdata->ws_rule,
 352                              ecbdata->file, set, reset, ws);
 353        }
 354}
 355
 356static void emit_hunk_header(struct emit_callback *ecbdata,
 357                             const char *line, int len)
 358{
 359        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 360        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 361        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 362        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 363        static const char atat[2] = { '@', '@' };
 364        const char *cp, *ep;
 365
 366        /*
 367         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 368         * it always is at least 10 bytes long.
 369         */
 370        if (len < 10 ||
 371            memcmp(line, atat, 2) ||
 372            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 373                emit_line(ecbdata->file, plain, reset, line, len);
 374                return;
 375        }
 376        ep += 2; /* skip over @@ */
 377
 378        /* The hunk header in fraginfo color */
 379        emit_line(ecbdata->file, frag, reset, line, ep - line);
 380
 381        /* blank before the func header */
 382        for (cp = ep; ep - line < len; ep++)
 383                if (*ep != ' ' && *ep != '\t')
 384                        break;
 385        if (ep != cp)
 386                emit_line(ecbdata->file, plain, reset, cp, ep - cp);
 387
 388        if (ep < line + len)
 389                emit_line(ecbdata->file, func, reset, ep, line + len - ep);
 390}
 391
 392static struct diff_tempfile *claim_diff_tempfile(void) {
 393        int i;
 394        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 395                if (!diff_temp[i].name)
 396                        return diff_temp + i;
 397        die("BUG: diff is failing to clean up its tempfiles");
 398}
 399
 400static int remove_tempfile_installed;
 401
 402static void remove_tempfile(void)
 403{
 404        int i;
 405        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 406                if (diff_temp[i].name == diff_temp[i].tmp_path)
 407                        unlink_or_warn(diff_temp[i].name);
 408                diff_temp[i].name = NULL;
 409        }
 410}
 411
 412static void remove_tempfile_on_signal(int signo)
 413{
 414        remove_tempfile();
 415        sigchain_pop(signo);
 416        raise(signo);
 417}
 418
 419static void print_line_count(FILE *file, int count)
 420{
 421        switch (count) {
 422        case 0:
 423                fprintf(file, "0,0");
 424                break;
 425        case 1:
 426                fprintf(file, "1");
 427                break;
 428        default:
 429                fprintf(file, "1,%d", count);
 430                break;
 431        }
 432}
 433
 434static void emit_rewrite_lines(struct emit_callback *ecb,
 435                               int prefix, const char *data, int size)
 436{
 437        const char *endp = NULL;
 438        static const char *nneof = " No newline at end of file\n";
 439        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 440        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 441
 442        while (0 < size) {
 443                int len;
 444
 445                endp = memchr(data, '\n', size);
 446                len = endp ? (endp - data + 1) : size;
 447                if (prefix != '+') {
 448                        ecb->lno_in_preimage++;
 449                        emit_line_0(ecb->file, old, reset, '-',
 450                                    data, len);
 451                } else {
 452                        ecb->lno_in_postimage++;
 453                        emit_add_line(reset, ecb, data, len);
 454                }
 455                size -= len;
 456                data += len;
 457        }
 458        if (!endp) {
 459                const char *plain = diff_get_color(ecb->color_diff,
 460                                                   DIFF_PLAIN);
 461                emit_line_0(ecb->file, plain, reset, '\\',
 462                            nneof, strlen(nneof));
 463        }
 464}
 465
 466static void emit_rewrite_diff(const char *name_a,
 467                              const char *name_b,
 468                              struct diff_filespec *one,
 469                              struct diff_filespec *two,
 470                              struct userdiff_driver *textconv_one,
 471                              struct userdiff_driver *textconv_two,
 472                              struct diff_options *o)
 473{
 474        int lc_a, lc_b;
 475        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 476        const char *name_a_tab, *name_b_tab;
 477        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 478        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 479        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 480        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 481        const char *a_prefix, *b_prefix;
 482        char *data_one, *data_two;
 483        size_t size_one, size_two;
 484        struct emit_callback ecbdata;
 485
 486        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 487                a_prefix = o->b_prefix;
 488                b_prefix = o->a_prefix;
 489        } else {
 490                a_prefix = o->a_prefix;
 491                b_prefix = o->b_prefix;
 492        }
 493
 494        name_a += (*name_a == '/');
 495        name_b += (*name_b == '/');
 496        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 497        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 498
 499        strbuf_reset(&a_name);
 500        strbuf_reset(&b_name);
 501        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 502        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 503
 504        size_one = fill_textconv(textconv_one, one, &data_one);
 505        size_two = fill_textconv(textconv_two, two, &data_two);
 506
 507        memset(&ecbdata, 0, sizeof(ecbdata));
 508        ecbdata.color_diff = color_diff;
 509        ecbdata.found_changesp = &o->found_changes;
 510        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 511        ecbdata.file = o->file;
 512        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 513                mmfile_t mf1, mf2;
 514                mf1.ptr = (char *)data_one;
 515                mf2.ptr = (char *)data_two;
 516                mf1.size = size_one;
 517                mf2.size = size_two;
 518                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 519        }
 520        ecbdata.lno_in_preimage = 1;
 521        ecbdata.lno_in_postimage = 1;
 522
 523        lc_a = count_lines(data_one, size_one);
 524        lc_b = count_lines(data_two, size_two);
 525        fprintf(o->file,
 526                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 527                metainfo, a_name.buf, name_a_tab, reset,
 528                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 529        print_line_count(o->file, lc_a);
 530        fprintf(o->file, " +");
 531        print_line_count(o->file, lc_b);
 532        fprintf(o->file, " @@%s\n", reset);
 533        if (lc_a)
 534                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 535        if (lc_b)
 536                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 537        if (textconv_one)
 538                free((char *)data_one);
 539        if (textconv_two)
 540                free((char *)data_two);
 541}
 542
 543struct diff_words_buffer {
 544        mmfile_t text;
 545        long alloc;
 546        struct diff_words_orig {
 547                const char *begin, *end;
 548        } *orig;
 549        int orig_nr, orig_alloc;
 550};
 551
 552static void diff_words_append(char *line, unsigned long len,
 553                struct diff_words_buffer *buffer)
 554{
 555        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 556        line++;
 557        len--;
 558        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 559        buffer->text.size += len;
 560        buffer->text.ptr[buffer->text.size] = '\0';
 561}
 562
 563struct diff_words_data {
 564        struct diff_words_buffer minus, plus;
 565        const char *current_plus;
 566        FILE *file;
 567        regex_t *word_regex;
 568};
 569
 570static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 571{
 572        struct diff_words_data *diff_words = priv;
 573        int minus_first, minus_len, plus_first, plus_len;
 574        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 575
 576        if (line[0] != '@' || parse_hunk_header(line, len,
 577                        &minus_first, &minus_len, &plus_first, &plus_len))
 578                return;
 579
 580        /* POSIX requires that first be decremented by one if len == 0... */
 581        if (minus_len) {
 582                minus_begin = diff_words->minus.orig[minus_first].begin;
 583                minus_end =
 584                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 585        } else
 586                minus_begin = minus_end =
 587                        diff_words->minus.orig[minus_first].end;
 588
 589        if (plus_len) {
 590                plus_begin = diff_words->plus.orig[plus_first].begin;
 591                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 592        } else
 593                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 594
 595        if (diff_words->current_plus != plus_begin)
 596                fwrite(diff_words->current_plus,
 597                                plus_begin - diff_words->current_plus, 1,
 598                                diff_words->file);
 599        if (minus_begin != minus_end)
 600                color_fwrite_lines(diff_words->file,
 601                                diff_get_color(1, DIFF_FILE_OLD),
 602                                minus_end - minus_begin, minus_begin);
 603        if (plus_begin != plus_end)
 604                color_fwrite_lines(diff_words->file,
 605                                diff_get_color(1, DIFF_FILE_NEW),
 606                                plus_end - plus_begin, plus_begin);
 607
 608        diff_words->current_plus = plus_end;
 609}
 610
 611/* This function starts looking at *begin, and returns 0 iff a word was found. */
 612static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 613                int *begin, int *end)
 614{
 615        if (word_regex && *begin < buffer->size) {
 616                regmatch_t match[1];
 617                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 618                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 619                                        '\n', match[0].rm_eo - match[0].rm_so);
 620                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 621                        *begin += match[0].rm_so;
 622                        return *begin >= *end;
 623                }
 624                return -1;
 625        }
 626
 627        /* find the next word */
 628        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 629                (*begin)++;
 630        if (*begin >= buffer->size)
 631                return -1;
 632
 633        /* find the end of the word */
 634        *end = *begin + 1;
 635        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 636                (*end)++;
 637
 638        return 0;
 639}
 640
 641/*
 642 * This function splits the words in buffer->text, stores the list with
 643 * newline separator into out, and saves the offsets of the original words
 644 * in buffer->orig.
 645 */
 646static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 647                regex_t *word_regex)
 648{
 649        int i, j;
 650        long alloc = 0;
 651
 652        out->size = 0;
 653        out->ptr = NULL;
 654
 655        /* fake an empty "0th" word */
 656        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 657        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 658        buffer->orig_nr = 1;
 659
 660        for (i = 0; i < buffer->text.size; i++) {
 661                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 662                        return;
 663
 664                /* store original boundaries */
 665                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 666                                buffer->orig_alloc);
 667                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 668                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 669                buffer->orig_nr++;
 670
 671                /* store one word */
 672                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 673                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 674                out->ptr[out->size + j - i] = '\n';
 675                out->size += j - i + 1;
 676
 677                i = j - 1;
 678        }
 679}
 680
 681/* this executes the word diff on the accumulated buffers */
 682static void diff_words_show(struct diff_words_data *diff_words)
 683{
 684        xpparam_t xpp;
 685        xdemitconf_t xecfg;
 686        mmfile_t minus, plus;
 687
 688        /* special case: only removal */
 689        if (!diff_words->plus.text.size) {
 690                color_fwrite_lines(diff_words->file,
 691                        diff_get_color(1, DIFF_FILE_OLD),
 692                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 693                diff_words->minus.text.size = 0;
 694                return;
 695        }
 696
 697        diff_words->current_plus = diff_words->plus.text.ptr;
 698
 699        memset(&xpp, 0, sizeof(xpp));
 700        memset(&xecfg, 0, sizeof(xecfg));
 701        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 702        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 703        xpp.flags = XDF_NEED_MINIMAL;
 704        /* as only the hunk header will be parsed, we need a 0-context */
 705        xecfg.ctxlen = 0;
 706        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 707                      &xpp, &xecfg);
 708        free(minus.ptr);
 709        free(plus.ptr);
 710        if (diff_words->current_plus != diff_words->plus.text.ptr +
 711                        diff_words->plus.text.size)
 712                fwrite(diff_words->current_plus,
 713                        diff_words->plus.text.ptr + diff_words->plus.text.size
 714                        - diff_words->current_plus, 1,
 715                        diff_words->file);
 716        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 717}
 718
 719/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 720static void diff_words_flush(struct emit_callback *ecbdata)
 721{
 722        if (ecbdata->diff_words->minus.text.size ||
 723            ecbdata->diff_words->plus.text.size)
 724                diff_words_show(ecbdata->diff_words);
 725}
 726
 727static void free_diff_words_data(struct emit_callback *ecbdata)
 728{
 729        if (ecbdata->diff_words) {
 730                diff_words_flush(ecbdata);
 731                free (ecbdata->diff_words->minus.text.ptr);
 732                free (ecbdata->diff_words->minus.orig);
 733                free (ecbdata->diff_words->plus.text.ptr);
 734                free (ecbdata->diff_words->plus.orig);
 735                free(ecbdata->diff_words->word_regex);
 736                free(ecbdata->diff_words);
 737                ecbdata->diff_words = NULL;
 738        }
 739}
 740
 741const char *diff_get_color(int diff_use_color, enum color_diff ix)
 742{
 743        if (diff_use_color)
 744                return diff_colors[ix];
 745        return "";
 746}
 747
 748static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 749{
 750        const char *cp;
 751        unsigned long allot;
 752        size_t l = len;
 753
 754        if (ecb->truncate)
 755                return ecb->truncate(line, len);
 756        cp = line;
 757        allot = l;
 758        while (0 < l) {
 759                (void) utf8_width(&cp, &l);
 760                if (!cp)
 761                        break; /* truncated in the middle? */
 762        }
 763        return allot - l;
 764}
 765
 766static void find_lno(const char *line, struct emit_callback *ecbdata)
 767{
 768        const char *p;
 769        ecbdata->lno_in_preimage = 0;
 770        ecbdata->lno_in_postimage = 0;
 771        p = strchr(line, '-');
 772        if (!p)
 773                return; /* cannot happen */
 774        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 775        p = strchr(p, '+');
 776        if (!p)
 777                return; /* cannot happen */
 778        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 779}
 780
 781static void fn_out_consume(void *priv, char *line, unsigned long len)
 782{
 783        struct emit_callback *ecbdata = priv;
 784        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 785        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 786        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 787
 788        if (ecbdata->header) {
 789                fprintf(ecbdata->file, "%s", ecbdata->header->buf);
 790                strbuf_reset(ecbdata->header);
 791                ecbdata->header = NULL;
 792        }
 793        *(ecbdata->found_changesp) = 1;
 794
 795        if (ecbdata->label_path[0]) {
 796                const char *name_a_tab, *name_b_tab;
 797
 798                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 799                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 800
 801                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 802                        meta, ecbdata->label_path[0], reset, name_a_tab);
 803                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 804                        meta, ecbdata->label_path[1], reset, name_b_tab);
 805                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 806        }
 807
 808        if (diff_suppress_blank_empty
 809            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 810                line[0] = '\n';
 811                len = 1;
 812        }
 813
 814        if (line[0] == '@') {
 815                if (ecbdata->diff_words)
 816                        diff_words_flush(ecbdata);
 817                len = sane_truncate_line(ecbdata, line, len);
 818                find_lno(line, ecbdata);
 819                emit_hunk_header(ecbdata, line, len);
 820                if (line[len-1] != '\n')
 821                        putc('\n', ecbdata->file);
 822                return;
 823        }
 824
 825        if (len < 1) {
 826                emit_line(ecbdata->file, reset, reset, line, len);
 827                return;
 828        }
 829
 830        if (ecbdata->diff_words) {
 831                if (line[0] == '-') {
 832                        diff_words_append(line, len,
 833                                          &ecbdata->diff_words->minus);
 834                        return;
 835                } else if (line[0] == '+') {
 836                        diff_words_append(line, len,
 837                                          &ecbdata->diff_words->plus);
 838                        return;
 839                }
 840                diff_words_flush(ecbdata);
 841                line++;
 842                len--;
 843                emit_line(ecbdata->file, plain, reset, line, len);
 844                return;
 845        }
 846
 847        if (line[0] != '+') {
 848                const char *color =
 849                        diff_get_color(ecbdata->color_diff,
 850                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 851                ecbdata->lno_in_preimage++;
 852                if (line[0] == ' ')
 853                        ecbdata->lno_in_postimage++;
 854                emit_line(ecbdata->file, color, reset, line, len);
 855        } else {
 856                ecbdata->lno_in_postimage++;
 857                emit_add_line(reset, ecbdata, line + 1, len - 1);
 858        }
 859}
 860
 861static char *pprint_rename(const char *a, const char *b)
 862{
 863        const char *old = a;
 864        const char *new = b;
 865        struct strbuf name = STRBUF_INIT;
 866        int pfx_length, sfx_length;
 867        int len_a = strlen(a);
 868        int len_b = strlen(b);
 869        int a_midlen, b_midlen;
 870        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 871        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 872
 873        if (qlen_a || qlen_b) {
 874                quote_c_style(a, &name, NULL, 0);
 875                strbuf_addstr(&name, " => ");
 876                quote_c_style(b, &name, NULL, 0);
 877                return strbuf_detach(&name, NULL);
 878        }
 879
 880        /* Find common prefix */
 881        pfx_length = 0;
 882        while (*old && *new && *old == *new) {
 883                if (*old == '/')
 884                        pfx_length = old - a + 1;
 885                old++;
 886                new++;
 887        }
 888
 889        /* Find common suffix */
 890        old = a + len_a;
 891        new = b + len_b;
 892        sfx_length = 0;
 893        while (a <= old && b <= new && *old == *new) {
 894                if (*old == '/')
 895                        sfx_length = len_a - (old - a);
 896                old--;
 897                new--;
 898        }
 899
 900        /*
 901         * pfx{mid-a => mid-b}sfx
 902         * {pfx-a => pfx-b}sfx
 903         * pfx{sfx-a => sfx-b}
 904         * name-a => name-b
 905         */
 906        a_midlen = len_a - pfx_length - sfx_length;
 907        b_midlen = len_b - pfx_length - sfx_length;
 908        if (a_midlen < 0)
 909                a_midlen = 0;
 910        if (b_midlen < 0)
 911                b_midlen = 0;
 912
 913        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 914        if (pfx_length + sfx_length) {
 915                strbuf_add(&name, a, pfx_length);
 916                strbuf_addch(&name, '{');
 917        }
 918        strbuf_add(&name, a + pfx_length, a_midlen);
 919        strbuf_addstr(&name, " => ");
 920        strbuf_add(&name, b + pfx_length, b_midlen);
 921        if (pfx_length + sfx_length) {
 922                strbuf_addch(&name, '}');
 923                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 924        }
 925        return strbuf_detach(&name, NULL);
 926}
 927
 928struct diffstat_t {
 929        int nr;
 930        int alloc;
 931        struct diffstat_file {
 932                char *from_name;
 933                char *name;
 934                char *print_name;
 935                unsigned is_unmerged:1;
 936                unsigned is_binary:1;
 937                unsigned is_renamed:1;
 938                uintmax_t added, deleted;
 939        } **files;
 940};
 941
 942static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 943                                          const char *name_a,
 944                                          const char *name_b)
 945{
 946        struct diffstat_file *x;
 947        x = xcalloc(sizeof (*x), 1);
 948        if (diffstat->nr == diffstat->alloc) {
 949                diffstat->alloc = alloc_nr(diffstat->alloc);
 950                diffstat->files = xrealloc(diffstat->files,
 951                                diffstat->alloc * sizeof(x));
 952        }
 953        diffstat->files[diffstat->nr++] = x;
 954        if (name_b) {
 955                x->from_name = xstrdup(name_a);
 956                x->name = xstrdup(name_b);
 957                x->is_renamed = 1;
 958        }
 959        else {
 960                x->from_name = NULL;
 961                x->name = xstrdup(name_a);
 962        }
 963        return x;
 964}
 965
 966static void diffstat_consume(void *priv, char *line, unsigned long len)
 967{
 968        struct diffstat_t *diffstat = priv;
 969        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 970
 971        if (line[0] == '+')
 972                x->added++;
 973        else if (line[0] == '-')
 974                x->deleted++;
 975}
 976
 977const char mime_boundary_leader[] = "------------";
 978
 979static int scale_linear(int it, int width, int max_change)
 980{
 981        /*
 982         * make sure that at least one '-' is printed if there were deletions,
 983         * and likewise for '+'.
 984         */
 985        if (max_change < 2)
 986                return it;
 987        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 988}
 989
 990static void show_name(FILE *file,
 991                      const char *prefix, const char *name, int len)
 992{
 993        fprintf(file, " %s%-*s |", prefix, len, name);
 994}
 995
 996static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 997{
 998        if (cnt <= 0)
 999                return;
1000        fprintf(file, "%s", set);
1001        while (cnt--)
1002                putc(ch, file);
1003        fprintf(file, "%s", reset);
1004}
1005
1006static void fill_print_name(struct diffstat_file *file)
1007{
1008        char *pname;
1009
1010        if (file->print_name)
1011                return;
1012
1013        if (!file->is_renamed) {
1014                struct strbuf buf = STRBUF_INIT;
1015                if (quote_c_style(file->name, &buf, NULL, 0)) {
1016                        pname = strbuf_detach(&buf, NULL);
1017                } else {
1018                        pname = file->name;
1019                        strbuf_release(&buf);
1020                }
1021        } else {
1022                pname = pprint_rename(file->from_name, file->name);
1023        }
1024        file->print_name = pname;
1025}
1026
1027static void show_stats(struct diffstat_t *data, struct diff_options *options)
1028{
1029        int i, len, add, del, adds = 0, dels = 0;
1030        uintmax_t max_change = 0, max_len = 0;
1031        int total_files = data->nr;
1032        int width, name_width;
1033        const char *reset, *set, *add_c, *del_c;
1034
1035        if (data->nr == 0)
1036                return;
1037
1038        width = options->stat_width ? options->stat_width : 80;
1039        name_width = options->stat_name_width ? options->stat_name_width : 50;
1040
1041        /* Sanity: give at least 5 columns to the graph,
1042         * but leave at least 10 columns for the name.
1043         */
1044        if (width < 25)
1045                width = 25;
1046        if (name_width < 10)
1047                name_width = 10;
1048        else if (width < name_width + 15)
1049                name_width = width - 15;
1050
1051        /* Find the longest filename and max number of changes */
1052        reset = diff_get_color_opt(options, DIFF_RESET);
1053        set   = diff_get_color_opt(options, DIFF_PLAIN);
1054        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1055        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1056
1057        for (i = 0; i < data->nr; i++) {
1058                struct diffstat_file *file = data->files[i];
1059                uintmax_t change = file->added + file->deleted;
1060                fill_print_name(file);
1061                len = strlen(file->print_name);
1062                if (max_len < len)
1063                        max_len = len;
1064
1065                if (file->is_binary || file->is_unmerged)
1066                        continue;
1067                if (max_change < change)
1068                        max_change = change;
1069        }
1070
1071        /* Compute the width of the graph part;
1072         * 10 is for one blank at the beginning of the line plus
1073         * " | count " between the name and the graph.
1074         *
1075         * From here on, name_width is the width of the name area,
1076         * and width is the width of the graph area.
1077         */
1078        name_width = (name_width < max_len) ? name_width : max_len;
1079        if (width < (name_width + 10) + max_change)
1080                width = width - (name_width + 10);
1081        else
1082                width = max_change;
1083
1084        for (i = 0; i < data->nr; i++) {
1085                const char *prefix = "";
1086                char *name = data->files[i]->print_name;
1087                uintmax_t added = data->files[i]->added;
1088                uintmax_t deleted = data->files[i]->deleted;
1089                int name_len;
1090
1091                /*
1092                 * "scale" the filename
1093                 */
1094                len = name_width;
1095                name_len = strlen(name);
1096                if (name_width < name_len) {
1097                        char *slash;
1098                        prefix = "...";
1099                        len -= 3;
1100                        name += name_len - len;
1101                        slash = strchr(name, '/');
1102                        if (slash)
1103                                name = slash;
1104                }
1105
1106                if (data->files[i]->is_binary) {
1107                        show_name(options->file, prefix, name, len);
1108                        fprintf(options->file, "  Bin ");
1109                        fprintf(options->file, "%s%"PRIuMAX"%s",
1110                                del_c, deleted, reset);
1111                        fprintf(options->file, " -> ");
1112                        fprintf(options->file, "%s%"PRIuMAX"%s",
1113                                add_c, added, reset);
1114                        fprintf(options->file, " bytes");
1115                        fprintf(options->file, "\n");
1116                        continue;
1117                }
1118                else if (data->files[i]->is_unmerged) {
1119                        show_name(options->file, prefix, name, len);
1120                        fprintf(options->file, "  Unmerged\n");
1121                        continue;
1122                }
1123                else if (!data->files[i]->is_renamed &&
1124                         (added + deleted == 0)) {
1125                        total_files--;
1126                        continue;
1127                }
1128
1129                /*
1130                 * scale the add/delete
1131                 */
1132                add = added;
1133                del = deleted;
1134                adds += add;
1135                dels += del;
1136
1137                if (width <= max_change) {
1138                        add = scale_linear(add, width, max_change);
1139                        del = scale_linear(del, width, max_change);
1140                }
1141                show_name(options->file, prefix, name, len);
1142                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1143                                added + deleted ? " " : "");
1144                show_graph(options->file, '+', add, add_c, reset);
1145                show_graph(options->file, '-', del, del_c, reset);
1146                fprintf(options->file, "\n");
1147        }
1148        fprintf(options->file,
1149               " %d files changed, %d insertions(+), %d deletions(-)\n",
1150               total_files, adds, dels);
1151}
1152
1153static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1154{
1155        int i, adds = 0, dels = 0, total_files = data->nr;
1156
1157        if (data->nr == 0)
1158                return;
1159
1160        for (i = 0; i < data->nr; i++) {
1161                if (!data->files[i]->is_binary &&
1162                    !data->files[i]->is_unmerged) {
1163                        int added = data->files[i]->added;
1164                        int deleted= data->files[i]->deleted;
1165                        if (!data->files[i]->is_renamed &&
1166                            (added + deleted == 0)) {
1167                                total_files--;
1168                        } else {
1169                                adds += added;
1170                                dels += deleted;
1171                        }
1172                }
1173        }
1174        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1175               total_files, adds, dels);
1176}
1177
1178static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1179{
1180        int i;
1181
1182        if (data->nr == 0)
1183                return;
1184
1185        for (i = 0; i < data->nr; i++) {
1186                struct diffstat_file *file = data->files[i];
1187
1188                if (file->is_binary)
1189                        fprintf(options->file, "-\t-\t");
1190                else
1191                        fprintf(options->file,
1192                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1193                                file->added, file->deleted);
1194                if (options->line_termination) {
1195                        fill_print_name(file);
1196                        if (!file->is_renamed)
1197                                write_name_quoted(file->name, options->file,
1198                                                  options->line_termination);
1199                        else {
1200                                fputs(file->print_name, options->file);
1201                                putc(options->line_termination, options->file);
1202                        }
1203                } else {
1204                        if (file->is_renamed) {
1205                                putc('\0', options->file);
1206                                write_name_quoted(file->from_name, options->file, '\0');
1207                        }
1208                        write_name_quoted(file->name, options->file, '\0');
1209                }
1210        }
1211}
1212
1213struct dirstat_file {
1214        const char *name;
1215        unsigned long changed;
1216};
1217
1218struct dirstat_dir {
1219        struct dirstat_file *files;
1220        int alloc, nr, percent, cumulative;
1221};
1222
1223static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
1224{
1225        unsigned long this_dir = 0;
1226        unsigned int sources = 0;
1227
1228        while (dir->nr) {
1229                struct dirstat_file *f = dir->files;
1230                int namelen = strlen(f->name);
1231                unsigned long this;
1232                char *slash;
1233
1234                if (namelen < baselen)
1235                        break;
1236                if (memcmp(f->name, base, baselen))
1237                        break;
1238                slash = strchr(f->name + baselen, '/');
1239                if (slash) {
1240                        int newbaselen = slash + 1 - f->name;
1241                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1242                        sources++;
1243                } else {
1244                        this = f->changed;
1245                        dir->files++;
1246                        dir->nr--;
1247                        sources += 2;
1248                }
1249                this_dir += this;
1250        }
1251
1252        /*
1253         * We don't report dirstat's for
1254         *  - the top level
1255         *  - or cases where everything came from a single directory
1256         *    under this directory (sources == 1).
1257         */
1258        if (baselen && sources != 1) {
1259                int permille = this_dir * 1000 / changed;
1260                if (permille) {
1261                        int percent = permille / 10;
1262                        if (percent >= dir->percent) {
1263                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1264                                if (!dir->cumulative)
1265                                        return 0;
1266                        }
1267                }
1268        }
1269        return this_dir;
1270}
1271
1272static int dirstat_compare(const void *_a, const void *_b)
1273{
1274        const struct dirstat_file *a = _a;
1275        const struct dirstat_file *b = _b;
1276        return strcmp(a->name, b->name);
1277}
1278
1279static void show_dirstat(struct diff_options *options)
1280{
1281        int i;
1282        unsigned long changed;
1283        struct dirstat_dir dir;
1284        struct diff_queue_struct *q = &diff_queued_diff;
1285
1286        dir.files = NULL;
1287        dir.alloc = 0;
1288        dir.nr = 0;
1289        dir.percent = options->dirstat_percent;
1290        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1291
1292        changed = 0;
1293        for (i = 0; i < q->nr; i++) {
1294                struct diff_filepair *p = q->queue[i];
1295                const char *name;
1296                unsigned long copied, added, damage;
1297
1298                name = p->one->path ? p->one->path : p->two->path;
1299
1300                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1301                        diff_populate_filespec(p->one, 0);
1302                        diff_populate_filespec(p->two, 0);
1303                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1304                                               &copied, &added);
1305                        diff_free_filespec_data(p->one);
1306                        diff_free_filespec_data(p->two);
1307                } else if (DIFF_FILE_VALID(p->one)) {
1308                        diff_populate_filespec(p->one, 1);
1309                        copied = added = 0;
1310                        diff_free_filespec_data(p->one);
1311                } else if (DIFF_FILE_VALID(p->two)) {
1312                        diff_populate_filespec(p->two, 1);
1313                        copied = 0;
1314                        added = p->two->size;
1315                        diff_free_filespec_data(p->two);
1316                } else
1317                        continue;
1318
1319                /*
1320                 * Original minus copied is the removed material,
1321                 * added is the new material.  They are both damages
1322                 * made to the preimage. In --dirstat-by-file mode, count
1323                 * damaged files, not damaged lines. This is done by
1324                 * counting only a single damaged line per file.
1325                 */
1326                damage = (p->one->size - copied) + added;
1327                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1328                        damage = 1;
1329
1330                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1331                dir.files[dir.nr].name = name;
1332                dir.files[dir.nr].changed = damage;
1333                changed += damage;
1334                dir.nr++;
1335        }
1336
1337        /* This can happen even with many files, if everything was renames */
1338        if (!changed)
1339                return;
1340
1341        /* Show all directories with more than x% of the changes */
1342        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1343        gather_dirstat(options->file, &dir, changed, "", 0);
1344}
1345
1346static void free_diffstat_info(struct diffstat_t *diffstat)
1347{
1348        int i;
1349        for (i = 0; i < diffstat->nr; i++) {
1350                struct diffstat_file *f = diffstat->files[i];
1351                if (f->name != f->print_name)
1352                        free(f->print_name);
1353                free(f->name);
1354                free(f->from_name);
1355                free(f);
1356        }
1357        free(diffstat->files);
1358}
1359
1360struct checkdiff_t {
1361        const char *filename;
1362        int lineno;
1363        int conflict_marker_size;
1364        struct diff_options *o;
1365        unsigned ws_rule;
1366        unsigned status;
1367};
1368
1369static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1370{
1371        char firstchar;
1372        int cnt;
1373
1374        if (len < marker_size + 1)
1375                return 0;
1376        firstchar = line[0];
1377        switch (firstchar) {
1378        case '=': case '>': case '<': case '|':
1379                break;
1380        default:
1381                return 0;
1382        }
1383        for (cnt = 1; cnt < marker_size; cnt++)
1384                if (line[cnt] != firstchar)
1385                        return 0;
1386        /* line[1] thru line[marker_size-1] are same as firstchar */
1387        if (len < marker_size + 1 || !isspace(line[marker_size]))
1388                return 0;
1389        return 1;
1390}
1391
1392static void checkdiff_consume(void *priv, char *line, unsigned long len)
1393{
1394        struct checkdiff_t *data = priv;
1395        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1396        int marker_size = data->conflict_marker_size;
1397        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1398        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1399        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1400        char *err;
1401
1402        if (line[0] == '+') {
1403                unsigned bad;
1404                data->lineno++;
1405                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1406                        data->status |= 1;
1407                        fprintf(data->o->file,
1408                                "%s:%d: leftover conflict marker\n",
1409                                data->filename, data->lineno);
1410                }
1411                bad = ws_check(line + 1, len - 1, data->ws_rule);
1412                if (!bad)
1413                        return;
1414                data->status |= bad;
1415                err = whitespace_error_string(bad);
1416                fprintf(data->o->file, "%s:%d: %s.\n",
1417                        data->filename, data->lineno, err);
1418                free(err);
1419                emit_line(data->o->file, set, reset, line, 1);
1420                ws_check_emit(line + 1, len - 1, data->ws_rule,
1421                              data->o->file, set, reset, ws);
1422        } else if (line[0] == ' ') {
1423                data->lineno++;
1424        } else if (line[0] == '@') {
1425                char *plus = strchr(line, '+');
1426                if (plus)
1427                        data->lineno = strtol(plus, NULL, 10) - 1;
1428                else
1429                        die("invalid diff");
1430        }
1431}
1432
1433static unsigned char *deflate_it(char *data,
1434                                 unsigned long size,
1435                                 unsigned long *result_size)
1436{
1437        int bound;
1438        unsigned char *deflated;
1439        z_stream stream;
1440
1441        memset(&stream, 0, sizeof(stream));
1442        deflateInit(&stream, zlib_compression_level);
1443        bound = deflateBound(&stream, size);
1444        deflated = xmalloc(bound);
1445        stream.next_out = deflated;
1446        stream.avail_out = bound;
1447
1448        stream.next_in = (unsigned char *)data;
1449        stream.avail_in = size;
1450        while (deflate(&stream, Z_FINISH) == Z_OK)
1451                ; /* nothing */
1452        deflateEnd(&stream);
1453        *result_size = stream.total_out;
1454        return deflated;
1455}
1456
1457static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1458{
1459        void *cp;
1460        void *delta;
1461        void *deflated;
1462        void *data;
1463        unsigned long orig_size;
1464        unsigned long delta_size;
1465        unsigned long deflate_size;
1466        unsigned long data_size;
1467
1468        /* We could do deflated delta, or we could do just deflated two,
1469         * whichever is smaller.
1470         */
1471        delta = NULL;
1472        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1473        if (one->size && two->size) {
1474                delta = diff_delta(one->ptr, one->size,
1475                                   two->ptr, two->size,
1476                                   &delta_size, deflate_size);
1477                if (delta) {
1478                        void *to_free = delta;
1479                        orig_size = delta_size;
1480                        delta = deflate_it(delta, delta_size, &delta_size);
1481                        free(to_free);
1482                }
1483        }
1484
1485        if (delta && delta_size < deflate_size) {
1486                fprintf(file, "delta %lu\n", orig_size);
1487                free(deflated);
1488                data = delta;
1489                data_size = delta_size;
1490        }
1491        else {
1492                fprintf(file, "literal %lu\n", two->size);
1493                free(delta);
1494                data = deflated;
1495                data_size = deflate_size;
1496        }
1497
1498        /* emit data encoded in base85 */
1499        cp = data;
1500        while (data_size) {
1501                int bytes = (52 < data_size) ? 52 : data_size;
1502                char line[70];
1503                data_size -= bytes;
1504                if (bytes <= 26)
1505                        line[0] = bytes + 'A' - 1;
1506                else
1507                        line[0] = bytes - 26 + 'a' - 1;
1508                encode_85(line + 1, cp, bytes);
1509                cp = (char *) cp + bytes;
1510                fputs(line, file);
1511                fputc('\n', file);
1512        }
1513        fprintf(file, "\n");
1514        free(data);
1515}
1516
1517static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1518{
1519        fprintf(file, "GIT binary patch\n");
1520        emit_binary_diff_body(file, one, two);
1521        emit_binary_diff_body(file, two, one);
1522}
1523
1524static void diff_filespec_load_driver(struct diff_filespec *one)
1525{
1526        if (!one->driver)
1527                one->driver = userdiff_find_by_path(one->path);
1528        if (!one->driver)
1529                one->driver = userdiff_find_by_name("default");
1530}
1531
1532int diff_filespec_is_binary(struct diff_filespec *one)
1533{
1534        if (one->is_binary == -1) {
1535                diff_filespec_load_driver(one);
1536                if (one->driver->binary != -1)
1537                        one->is_binary = one->driver->binary;
1538                else {
1539                        if (!one->data && DIFF_FILE_VALID(one))
1540                                diff_populate_filespec(one, 0);
1541                        if (one->data)
1542                                one->is_binary = buffer_is_binary(one->data,
1543                                                one->size);
1544                        if (one->is_binary == -1)
1545                                one->is_binary = 0;
1546                }
1547        }
1548        return one->is_binary;
1549}
1550
1551static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1552{
1553        diff_filespec_load_driver(one);
1554        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1555}
1556
1557static const char *userdiff_word_regex(struct diff_filespec *one)
1558{
1559        diff_filespec_load_driver(one);
1560        return one->driver->word_regex;
1561}
1562
1563void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1564{
1565        if (!options->a_prefix)
1566                options->a_prefix = a;
1567        if (!options->b_prefix)
1568                options->b_prefix = b;
1569}
1570
1571static struct userdiff_driver *get_textconv(struct diff_filespec *one)
1572{
1573        if (!DIFF_FILE_VALID(one))
1574                return NULL;
1575        if (!S_ISREG(one->mode))
1576                return NULL;
1577        diff_filespec_load_driver(one);
1578        if (!one->driver->textconv)
1579                return NULL;
1580
1581        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1582                struct notes_cache *c = xmalloc(sizeof(*c));
1583                struct strbuf name = STRBUF_INIT;
1584
1585                strbuf_addf(&name, "textconv/%s", one->driver->name);
1586                notes_cache_init(c, name.buf, one->driver->textconv);
1587                one->driver->textconv_cache = c;
1588        }
1589
1590        return one->driver;
1591}
1592
1593static void builtin_diff(const char *name_a,
1594                         const char *name_b,
1595                         struct diff_filespec *one,
1596                         struct diff_filespec *two,
1597                         const char *xfrm_msg,
1598                         struct diff_options *o,
1599                         int complete_rewrite)
1600{
1601        mmfile_t mf1, mf2;
1602        const char *lbl[2];
1603        char *a_one, *b_two;
1604        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1605        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1606        const char *a_prefix, *b_prefix;
1607        struct userdiff_driver *textconv_one = NULL;
1608        struct userdiff_driver *textconv_two = NULL;
1609        struct strbuf header = STRBUF_INIT;
1610
1611        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1612                        (!one->mode || S_ISGITLINK(one->mode)) &&
1613                        (!two->mode || S_ISGITLINK(two->mode))) {
1614                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1615                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1616                show_submodule_summary(o->file, one ? one->path : two->path,
1617                                one->sha1, two->sha1, two->dirty_submodule,
1618                                del, add, reset);
1619                return;
1620        }
1621
1622        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1623                textconv_one = get_textconv(one);
1624                textconv_two = get_textconv(two);
1625        }
1626
1627        diff_set_mnemonic_prefix(o, "a/", "b/");
1628        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1629                a_prefix = o->b_prefix;
1630                b_prefix = o->a_prefix;
1631        } else {
1632                a_prefix = o->a_prefix;
1633                b_prefix = o->b_prefix;
1634        }
1635
1636        /* Never use a non-valid filename anywhere if at all possible */
1637        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1638        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1639
1640        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1641        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1642        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1643        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1644        strbuf_addf(&header, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1645        if (lbl[0][0] == '/') {
1646                /* /dev/null */
1647                strbuf_addf(&header, "%snew file mode %06o%s\n", set, two->mode, reset);
1648                if (xfrm_msg && xfrm_msg[0])
1649                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1650        }
1651        else if (lbl[1][0] == '/') {
1652                strbuf_addf(&header, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1653                if (xfrm_msg && xfrm_msg[0])
1654                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1655        }
1656        else {
1657                if (one->mode != two->mode) {
1658                        strbuf_addf(&header, "%sold mode %06o%s\n", set, one->mode, reset);
1659                        strbuf_addf(&header, "%snew mode %06o%s\n", set, two->mode, reset);
1660                }
1661                if (xfrm_msg && xfrm_msg[0])
1662                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1663
1664                /*
1665                 * we do not run diff between different kind
1666                 * of objects.
1667                 */
1668                if ((one->mode ^ two->mode) & S_IFMT)
1669                        goto free_ab_and_return;
1670                if (complete_rewrite &&
1671                    (textconv_one || !diff_filespec_is_binary(one)) &&
1672                    (textconv_two || !diff_filespec_is_binary(two))) {
1673                        fprintf(o->file, "%s", header.buf);
1674                        strbuf_reset(&header);
1675                        emit_rewrite_diff(name_a, name_b, one, two,
1676                                                textconv_one, textconv_two, o);
1677                        o->found_changes = 1;
1678                        goto free_ab_and_return;
1679                }
1680        }
1681
1682        if (!DIFF_OPT_TST(o, TEXT) &&
1683            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1684              (!textconv_two && diff_filespec_is_binary(two)) )) {
1685                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1686                        die("unable to read files to diff");
1687                /* Quite common confusing case */
1688                if (mf1.size == mf2.size &&
1689                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1690                        goto free_ab_and_return;
1691                fprintf(o->file, "%s", header.buf);
1692                strbuf_reset(&header);
1693                if (DIFF_OPT_TST(o, BINARY))
1694                        emit_binary_diff(o->file, &mf1, &mf2);
1695                else
1696                        fprintf(o->file, "Binary files %s and %s differ\n",
1697                                lbl[0], lbl[1]);
1698                o->found_changes = 1;
1699        }
1700        else {
1701                /* Crazy xdl interfaces.. */
1702                const char *diffopts = getenv("GIT_DIFF_OPTS");
1703                xpparam_t xpp;
1704                xdemitconf_t xecfg;
1705                struct emit_callback ecbdata;
1706                const struct userdiff_funcname *pe;
1707
1708                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1709                        fprintf(o->file, "%s", header.buf);
1710                        strbuf_reset(&header);
1711                }
1712
1713                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1714                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1715
1716                pe = diff_funcname_pattern(one);
1717                if (!pe)
1718                        pe = diff_funcname_pattern(two);
1719
1720                memset(&xpp, 0, sizeof(xpp));
1721                memset(&xecfg, 0, sizeof(xecfg));
1722                memset(&ecbdata, 0, sizeof(ecbdata));
1723                ecbdata.label_path = lbl;
1724                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1725                ecbdata.found_changesp = &o->found_changes;
1726                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1727                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1728                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1729                ecbdata.file = o->file;
1730                ecbdata.header = header.len ? &header : NULL;
1731                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1732                xecfg.ctxlen = o->context;
1733                xecfg.interhunkctxlen = o->interhunkcontext;
1734                xecfg.flags = XDL_EMIT_FUNCNAMES;
1735                if (pe)
1736                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1737                if (!diffopts)
1738                        ;
1739                else if (!prefixcmp(diffopts, "--unified="))
1740                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1741                else if (!prefixcmp(diffopts, "-u"))
1742                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1743                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1744                        ecbdata.diff_words =
1745                                xcalloc(1, sizeof(struct diff_words_data));
1746                        ecbdata.diff_words->file = o->file;
1747                        if (!o->word_regex)
1748                                o->word_regex = userdiff_word_regex(one);
1749                        if (!o->word_regex)
1750                                o->word_regex = userdiff_word_regex(two);
1751                        if (!o->word_regex)
1752                                o->word_regex = diff_word_regex_cfg;
1753                        if (o->word_regex) {
1754                                ecbdata.diff_words->word_regex = (regex_t *)
1755                                        xmalloc(sizeof(regex_t));
1756                                if (regcomp(ecbdata.diff_words->word_regex,
1757                                                o->word_regex,
1758                                                REG_EXTENDED | REG_NEWLINE))
1759                                        die ("Invalid regular expression: %s",
1760                                                        o->word_regex);
1761                        }
1762                }
1763                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1764                              &xpp, &xecfg);
1765                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1766                        free_diff_words_data(&ecbdata);
1767                if (textconv_one)
1768                        free(mf1.ptr);
1769                if (textconv_two)
1770                        free(mf2.ptr);
1771                xdiff_clear_find_func(&xecfg);
1772        }
1773
1774 free_ab_and_return:
1775        strbuf_release(&header);
1776        diff_free_filespec_data(one);
1777        diff_free_filespec_data(two);
1778        free(a_one);
1779        free(b_two);
1780        return;
1781}
1782
1783static void builtin_diffstat(const char *name_a, const char *name_b,
1784                             struct diff_filespec *one,
1785                             struct diff_filespec *two,
1786                             struct diffstat_t *diffstat,
1787                             struct diff_options *o,
1788                             int complete_rewrite)
1789{
1790        mmfile_t mf1, mf2;
1791        struct diffstat_file *data;
1792
1793        data = diffstat_add(diffstat, name_a, name_b);
1794
1795        if (!one || !two) {
1796                data->is_unmerged = 1;
1797                return;
1798        }
1799        if (complete_rewrite) {
1800                diff_populate_filespec(one, 0);
1801                diff_populate_filespec(two, 0);
1802                data->deleted = count_lines(one->data, one->size);
1803                data->added = count_lines(two->data, two->size);
1804                goto free_and_return;
1805        }
1806        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1807                die("unable to read files to diff");
1808
1809        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1810                data->is_binary = 1;
1811                data->added = mf2.size;
1812                data->deleted = mf1.size;
1813        } else {
1814                /* Crazy xdl interfaces.. */
1815                xpparam_t xpp;
1816                xdemitconf_t xecfg;
1817
1818                memset(&xpp, 0, sizeof(xpp));
1819                memset(&xecfg, 0, sizeof(xecfg));
1820                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1821                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1822                              &xpp, &xecfg);
1823        }
1824
1825 free_and_return:
1826        diff_free_filespec_data(one);
1827        diff_free_filespec_data(two);
1828}
1829
1830static void builtin_checkdiff(const char *name_a, const char *name_b,
1831                              const char *attr_path,
1832                              struct diff_filespec *one,
1833                              struct diff_filespec *two,
1834                              struct diff_options *o)
1835{
1836        mmfile_t mf1, mf2;
1837        struct checkdiff_t data;
1838
1839        if (!two)
1840                return;
1841
1842        memset(&data, 0, sizeof(data));
1843        data.filename = name_b ? name_b : name_a;
1844        data.lineno = 0;
1845        data.o = o;
1846        data.ws_rule = whitespace_rule(attr_path);
1847        data.conflict_marker_size = ll_merge_marker_size(attr_path);
1848
1849        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1850                die("unable to read files to diff");
1851
1852        /*
1853         * All the other codepaths check both sides, but not checking
1854         * the "old" side here is deliberate.  We are checking the newly
1855         * introduced changes, and as long as the "new" side is text, we
1856         * can and should check what it introduces.
1857         */
1858        if (diff_filespec_is_binary(two))
1859                goto free_and_return;
1860        else {
1861                /* Crazy xdl interfaces.. */
1862                xpparam_t xpp;
1863                xdemitconf_t xecfg;
1864
1865                memset(&xpp, 0, sizeof(xpp));
1866                memset(&xecfg, 0, sizeof(xecfg));
1867                xecfg.ctxlen = 1; /* at least one context line */
1868                xpp.flags = XDF_NEED_MINIMAL;
1869                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1870                              &xpp, &xecfg);
1871
1872                if (data.ws_rule & WS_BLANK_AT_EOF) {
1873                        struct emit_callback ecbdata;
1874                        int blank_at_eof;
1875
1876                        ecbdata.ws_rule = data.ws_rule;
1877                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1878                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
1879
1880                        if (blank_at_eof) {
1881                                static char *err;
1882                                if (!err)
1883                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
1884                                fprintf(o->file, "%s:%d: %s.\n",
1885                                        data.filename, blank_at_eof, err);
1886                                data.status = 1; /* report errors */
1887                        }
1888                }
1889        }
1890 free_and_return:
1891        diff_free_filespec_data(one);
1892        diff_free_filespec_data(two);
1893        if (data.status)
1894                DIFF_OPT_SET(o, CHECK_FAILED);
1895}
1896
1897struct diff_filespec *alloc_filespec(const char *path)
1898{
1899        int namelen = strlen(path);
1900        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1901
1902        memset(spec, 0, sizeof(*spec));
1903        spec->path = (char *)(spec + 1);
1904        memcpy(spec->path, path, namelen+1);
1905        spec->count = 1;
1906        spec->is_binary = -1;
1907        return spec;
1908}
1909
1910void free_filespec(struct diff_filespec *spec)
1911{
1912        if (!--spec->count) {
1913                diff_free_filespec_data(spec);
1914                free(spec);
1915        }
1916}
1917
1918void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1919                   unsigned short mode)
1920{
1921        if (mode) {
1922                spec->mode = canon_mode(mode);
1923                hashcpy(spec->sha1, sha1);
1924                spec->sha1_valid = !is_null_sha1(sha1);
1925        }
1926}
1927
1928/*
1929 * Given a name and sha1 pair, if the index tells us the file in
1930 * the work tree has that object contents, return true, so that
1931 * prepare_temp_file() does not have to inflate and extract.
1932 */
1933static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1934{
1935        struct cache_entry *ce;
1936        struct stat st;
1937        int pos, len;
1938
1939        /*
1940         * We do not read the cache ourselves here, because the
1941         * benchmark with my previous version that always reads cache
1942         * shows that it makes things worse for diff-tree comparing
1943         * two linux-2.6 kernel trees in an already checked out work
1944         * tree.  This is because most diff-tree comparisons deal with
1945         * only a small number of files, while reading the cache is
1946         * expensive for a large project, and its cost outweighs the
1947         * savings we get by not inflating the object to a temporary
1948         * file.  Practically, this code only helps when we are used
1949         * by diff-cache --cached, which does read the cache before
1950         * calling us.
1951         */
1952        if (!active_cache)
1953                return 0;
1954
1955        /* We want to avoid the working directory if our caller
1956         * doesn't need the data in a normal file, this system
1957         * is rather slow with its stat/open/mmap/close syscalls,
1958         * and the object is contained in a pack file.  The pack
1959         * is probably already open and will be faster to obtain
1960         * the data through than the working directory.  Loose
1961         * objects however would tend to be slower as they need
1962         * to be individually opened and inflated.
1963         */
1964        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
1965                return 0;
1966
1967        len = strlen(name);
1968        pos = cache_name_pos(name, len);
1969        if (pos < 0)
1970                return 0;
1971        ce = active_cache[pos];
1972
1973        /*
1974         * This is not the sha1 we are looking for, or
1975         * unreusable because it is not a regular file.
1976         */
1977        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1978                return 0;
1979
1980        /*
1981         * If ce is marked as "assume unchanged", there is no
1982         * guarantee that work tree matches what we are looking for.
1983         */
1984        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
1985                return 0;
1986
1987        /*
1988         * If ce matches the file in the work tree, we can reuse it.
1989         */
1990        if (ce_uptodate(ce) ||
1991            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1992                return 1;
1993
1994        return 0;
1995}
1996
1997static int populate_from_stdin(struct diff_filespec *s)
1998{
1999        struct strbuf buf = STRBUF_INIT;
2000        size_t size = 0;
2001
2002        if (strbuf_read(&buf, 0, 0) < 0)
2003                return error("error while reading from stdin %s",
2004                                     strerror(errno));
2005
2006        s->should_munmap = 0;
2007        s->data = strbuf_detach(&buf, &size);
2008        s->size = size;
2009        s->should_free = 1;
2010        return 0;
2011}
2012
2013static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2014{
2015        int len;
2016        char *data = xmalloc(100), *dirty = "";
2017
2018        /* Are we looking at the work tree? */
2019        if (s->dirty_submodule)
2020                dirty = "-dirty";
2021
2022        len = snprintf(data, 100,
2023                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2024        s->data = data;
2025        s->size = len;
2026        s->should_free = 1;
2027        if (size_only) {
2028                s->data = NULL;
2029                free(data);
2030        }
2031        return 0;
2032}
2033
2034/*
2035 * While doing rename detection and pickaxe operation, we may need to
2036 * grab the data for the blob (or file) for our own in-core comparison.
2037 * diff_filespec has data and size fields for this purpose.
2038 */
2039int diff_populate_filespec(struct diff_filespec *s, int size_only)
2040{
2041        int err = 0;
2042        if (!DIFF_FILE_VALID(s))
2043                die("internal error: asking to populate invalid file.");
2044        if (S_ISDIR(s->mode))
2045                return -1;
2046
2047        if (s->data)
2048                return 0;
2049
2050        if (size_only && 0 < s->size)
2051                return 0;
2052
2053        if (S_ISGITLINK(s->mode))
2054                return diff_populate_gitlink(s, size_only);
2055
2056        if (!s->sha1_valid ||
2057            reuse_worktree_file(s->path, s->sha1, 0)) {
2058                struct strbuf buf = STRBUF_INIT;
2059                struct stat st;
2060                int fd;
2061
2062                if (!strcmp(s->path, "-"))
2063                        return populate_from_stdin(s);
2064
2065                if (lstat(s->path, &st) < 0) {
2066                        if (errno == ENOENT) {
2067                        err_empty:
2068                                err = -1;
2069                        empty:
2070                                s->data = (char *)"";
2071                                s->size = 0;
2072                                return err;
2073                        }
2074                }
2075                s->size = xsize_t(st.st_size);
2076                if (!s->size)
2077                        goto empty;
2078                if (S_ISLNK(st.st_mode)) {
2079                        struct strbuf sb = STRBUF_INIT;
2080
2081                        if (strbuf_readlink(&sb, s->path, s->size))
2082                                goto err_empty;
2083                        s->size = sb.len;
2084                        s->data = strbuf_detach(&sb, NULL);
2085                        s->should_free = 1;
2086                        return 0;
2087                }
2088                if (size_only)
2089                        return 0;
2090                fd = open(s->path, O_RDONLY);
2091                if (fd < 0)
2092                        goto err_empty;
2093                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2094                close(fd);
2095                s->should_munmap = 1;
2096
2097                /*
2098                 * Convert from working tree format to canonical git format
2099                 */
2100                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2101                        size_t size = 0;
2102                        munmap(s->data, s->size);
2103                        s->should_munmap = 0;
2104                        s->data = strbuf_detach(&buf, &size);
2105                        s->size = size;
2106                        s->should_free = 1;
2107                }
2108        }
2109        else {
2110                enum object_type type;
2111                if (size_only)
2112                        type = sha1_object_info(s->sha1, &s->size);
2113                else {
2114                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2115                        s->should_free = 1;
2116                }
2117        }
2118        return 0;
2119}
2120
2121void diff_free_filespec_blob(struct diff_filespec *s)
2122{
2123        if (s->should_free)
2124                free(s->data);
2125        else if (s->should_munmap)
2126                munmap(s->data, s->size);
2127
2128        if (s->should_free || s->should_munmap) {
2129                s->should_free = s->should_munmap = 0;
2130                s->data = NULL;
2131        }
2132}
2133
2134void diff_free_filespec_data(struct diff_filespec *s)
2135{
2136        diff_free_filespec_blob(s);
2137        free(s->cnt_data);
2138        s->cnt_data = NULL;
2139}
2140
2141static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2142                           void *blob,
2143                           unsigned long size,
2144                           const unsigned char *sha1,
2145                           int mode)
2146{
2147        int fd;
2148        struct strbuf buf = STRBUF_INIT;
2149        struct strbuf template = STRBUF_INIT;
2150        char *path_dup = xstrdup(path);
2151        const char *base = basename(path_dup);
2152
2153        /* Generate "XXXXXX_basename.ext" */
2154        strbuf_addstr(&template, "XXXXXX_");
2155        strbuf_addstr(&template, base);
2156
2157        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2158                        strlen(base) + 1);
2159        if (fd < 0)
2160                die_errno("unable to create temp-file");
2161        if (convert_to_working_tree(path,
2162                        (const char *)blob, (size_t)size, &buf)) {
2163                blob = buf.buf;
2164                size = buf.len;
2165        }
2166        if (write_in_full(fd, blob, size) != size)
2167                die_errno("unable to write temp-file");
2168        close(fd);
2169        temp->name = temp->tmp_path;
2170        strcpy(temp->hex, sha1_to_hex(sha1));
2171        temp->hex[40] = 0;
2172        sprintf(temp->mode, "%06o", mode);
2173        strbuf_release(&buf);
2174        strbuf_release(&template);
2175        free(path_dup);
2176}
2177
2178static struct diff_tempfile *prepare_temp_file(const char *name,
2179                struct diff_filespec *one)
2180{
2181        struct diff_tempfile *temp = claim_diff_tempfile();
2182
2183        if (!DIFF_FILE_VALID(one)) {
2184        not_a_valid_file:
2185                /* A '-' entry produces this for file-2, and
2186                 * a '+' entry produces this for file-1.
2187                 */
2188                temp->name = "/dev/null";
2189                strcpy(temp->hex, ".");
2190                strcpy(temp->mode, ".");
2191                return temp;
2192        }
2193
2194        if (!remove_tempfile_installed) {
2195                atexit(remove_tempfile);
2196                sigchain_push_common(remove_tempfile_on_signal);
2197                remove_tempfile_installed = 1;
2198        }
2199
2200        if (!one->sha1_valid ||
2201            reuse_worktree_file(name, one->sha1, 1)) {
2202                struct stat st;
2203                if (lstat(name, &st) < 0) {
2204                        if (errno == ENOENT)
2205                                goto not_a_valid_file;
2206                        die_errno("stat(%s)", name);
2207                }
2208                if (S_ISLNK(st.st_mode)) {
2209                        struct strbuf sb = STRBUF_INIT;
2210                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2211                                die_errno("readlink(%s)", name);
2212                        prep_temp_blob(name, temp, sb.buf, sb.len,
2213                                       (one->sha1_valid ?
2214                                        one->sha1 : null_sha1),
2215                                       (one->sha1_valid ?
2216                                        one->mode : S_IFLNK));
2217                        strbuf_release(&sb);
2218                }
2219                else {
2220                        /* we can borrow from the file in the work tree */
2221                        temp->name = name;
2222                        if (!one->sha1_valid)
2223                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2224                        else
2225                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2226                        /* Even though we may sometimes borrow the
2227                         * contents from the work tree, we always want
2228                         * one->mode.  mode is trustworthy even when
2229                         * !(one->sha1_valid), as long as
2230                         * DIFF_FILE_VALID(one).
2231                         */
2232                        sprintf(temp->mode, "%06o", one->mode);
2233                }
2234                return temp;
2235        }
2236        else {
2237                if (diff_populate_filespec(one, 0))
2238                        die("cannot read data blob for %s", one->path);
2239                prep_temp_blob(name, temp, one->data, one->size,
2240                               one->sha1, one->mode);
2241        }
2242        return temp;
2243}
2244
2245/* An external diff command takes:
2246 *
2247 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2248 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2249 *
2250 */
2251static void run_external_diff(const char *pgm,
2252                              const char *name,
2253                              const char *other,
2254                              struct diff_filespec *one,
2255                              struct diff_filespec *two,
2256                              const char *xfrm_msg,
2257                              int complete_rewrite)
2258{
2259        const char *spawn_arg[10];
2260        int retval;
2261        const char **arg = &spawn_arg[0];
2262
2263        if (one && two) {
2264                struct diff_tempfile *temp_one, *temp_two;
2265                const char *othername = (other ? other : name);
2266                temp_one = prepare_temp_file(name, one);
2267                temp_two = prepare_temp_file(othername, two);
2268                *arg++ = pgm;
2269                *arg++ = name;
2270                *arg++ = temp_one->name;
2271                *arg++ = temp_one->hex;
2272                *arg++ = temp_one->mode;
2273                *arg++ = temp_two->name;
2274                *arg++ = temp_two->hex;
2275                *arg++ = temp_two->mode;
2276                if (other) {
2277                        *arg++ = other;
2278                        *arg++ = xfrm_msg;
2279                }
2280        } else {
2281                *arg++ = pgm;
2282                *arg++ = name;
2283        }
2284        *arg = NULL;
2285        fflush(NULL);
2286        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2287        remove_tempfile();
2288        if (retval) {
2289                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2290                exit(1);
2291        }
2292}
2293
2294static int similarity_index(struct diff_filepair *p)
2295{
2296        return p->score * 100 / MAX_SCORE;
2297}
2298
2299static void fill_metainfo(struct strbuf *msg,
2300                          const char *name,
2301                          const char *other,
2302                          struct diff_filespec *one,
2303                          struct diff_filespec *two,
2304                          struct diff_options *o,
2305                          struct diff_filepair *p)
2306{
2307        strbuf_init(msg, PATH_MAX * 2 + 300);
2308        switch (p->status) {
2309        case DIFF_STATUS_COPIED:
2310                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2311                strbuf_addstr(msg, "\ncopy from ");
2312                quote_c_style(name, msg, NULL, 0);
2313                strbuf_addstr(msg, "\ncopy to ");
2314                quote_c_style(other, msg, NULL, 0);
2315                strbuf_addch(msg, '\n');
2316                break;
2317        case DIFF_STATUS_RENAMED:
2318                strbuf_addf(msg, "similarity index %d%%", similarity_index(p));
2319                strbuf_addstr(msg, "\nrename from ");
2320                quote_c_style(name, msg, NULL, 0);
2321                strbuf_addstr(msg, "\nrename to ");
2322                quote_c_style(other, msg, NULL, 0);
2323                strbuf_addch(msg, '\n');
2324                break;
2325        case DIFF_STATUS_MODIFIED:
2326                if (p->score) {
2327                        strbuf_addf(msg, "dissimilarity index %d%%\n",
2328                                    similarity_index(p));
2329                        break;
2330                }
2331                /* fallthru */
2332        default:
2333                /* nothing */
2334                ;
2335        }
2336        if (one && two && hashcmp(one->sha1, two->sha1)) {
2337                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2338
2339                if (DIFF_OPT_TST(o, BINARY)) {
2340                        mmfile_t mf;
2341                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2342                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2343                                abbrev = 40;
2344                }
2345                strbuf_addf(msg, "index %.*s..%.*s",
2346                            abbrev, sha1_to_hex(one->sha1),
2347                            abbrev, sha1_to_hex(two->sha1));
2348                if (one->mode == two->mode)
2349                        strbuf_addf(msg, " %06o", one->mode);
2350                strbuf_addch(msg, '\n');
2351        }
2352        if (msg->len)
2353                strbuf_setlen(msg, msg->len - 1);
2354}
2355
2356static void run_diff_cmd(const char *pgm,
2357                         const char *name,
2358                         const char *other,
2359                         const char *attr_path,
2360                         struct diff_filespec *one,
2361                         struct diff_filespec *two,
2362                         struct strbuf *msg,
2363                         struct diff_options *o,
2364                         struct diff_filepair *p)
2365{
2366        const char *xfrm_msg = NULL;
2367        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2368
2369        if (msg) {
2370                fill_metainfo(msg, name, other, one, two, o, p);
2371                xfrm_msg = msg->len ? msg->buf : NULL;
2372        }
2373
2374        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2375                pgm = NULL;
2376        else {
2377                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2378                if (drv && drv->external)
2379                        pgm = drv->external;
2380        }
2381
2382        if (pgm) {
2383                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2384                                  complete_rewrite);
2385                return;
2386        }
2387        if (one && two)
2388                builtin_diff(name, other ? other : name,
2389                             one, two, xfrm_msg, o, complete_rewrite);
2390        else
2391                fprintf(o->file, "* Unmerged path %s\n", name);
2392}
2393
2394static void diff_fill_sha1_info(struct diff_filespec *one)
2395{
2396        if (DIFF_FILE_VALID(one)) {
2397                if (!one->sha1_valid) {
2398                        struct stat st;
2399                        if (!strcmp(one->path, "-")) {
2400                                hashcpy(one->sha1, null_sha1);
2401                                return;
2402                        }
2403                        if (lstat(one->path, &st) < 0)
2404                                die_errno("stat '%s'", one->path);
2405                        if (index_path(one->sha1, one->path, &st, 0))
2406                                die("cannot hash %s", one->path);
2407                }
2408        }
2409        else
2410                hashclr(one->sha1);
2411}
2412
2413static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2414{
2415        /* Strip the prefix but do not molest /dev/null and absolute paths */
2416        if (*namep && **namep != '/')
2417                *namep += prefix_length;
2418        if (*otherp && **otherp != '/')
2419                *otherp += prefix_length;
2420}
2421
2422static void run_diff(struct diff_filepair *p, struct diff_options *o)
2423{
2424        const char *pgm = external_diff();
2425        struct strbuf msg;
2426        struct diff_filespec *one = p->one;
2427        struct diff_filespec *two = p->two;
2428        const char *name;
2429        const char *other;
2430        const char *attr_path;
2431
2432        name  = p->one->path;
2433        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2434        attr_path = name;
2435        if (o->prefix_length)
2436                strip_prefix(o->prefix_length, &name, &other);
2437
2438        if (DIFF_PAIR_UNMERGED(p)) {
2439                run_diff_cmd(pgm, name, NULL, attr_path,
2440                             NULL, NULL, NULL, o, p);
2441                return;
2442        }
2443
2444        diff_fill_sha1_info(one);
2445        diff_fill_sha1_info(two);
2446
2447        if (!pgm &&
2448            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2449            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2450                /*
2451                 * a filepair that changes between file and symlink
2452                 * needs to be split into deletion and creation.
2453                 */
2454                struct diff_filespec *null = alloc_filespec(two->path);
2455                run_diff_cmd(NULL, name, other, attr_path,
2456                             one, null, &msg, o, p);
2457                free(null);
2458                strbuf_release(&msg);
2459
2460                null = alloc_filespec(one->path);
2461                run_diff_cmd(NULL, name, other, attr_path,
2462                             null, two, &msg, o, p);
2463                free(null);
2464        }
2465        else
2466                run_diff_cmd(pgm, name, other, attr_path,
2467                             one, two, &msg, o, p);
2468
2469        strbuf_release(&msg);
2470}
2471
2472static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2473                         struct diffstat_t *diffstat)
2474{
2475        const char *name;
2476        const char *other;
2477        int complete_rewrite = 0;
2478
2479        if (DIFF_PAIR_UNMERGED(p)) {
2480                /* unmerged */
2481                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2482                return;
2483        }
2484
2485        name = p->one->path;
2486        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2487
2488        if (o->prefix_length)
2489                strip_prefix(o->prefix_length, &name, &other);
2490
2491        diff_fill_sha1_info(p->one);
2492        diff_fill_sha1_info(p->two);
2493
2494        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2495                complete_rewrite = 1;
2496        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2497}
2498
2499static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2500{
2501        const char *name;
2502        const char *other;
2503        const char *attr_path;
2504
2505        if (DIFF_PAIR_UNMERGED(p)) {
2506                /* unmerged */
2507                return;
2508        }
2509
2510        name = p->one->path;
2511        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2512        attr_path = other ? other : name;
2513
2514        if (o->prefix_length)
2515                strip_prefix(o->prefix_length, &name, &other);
2516
2517        diff_fill_sha1_info(p->one);
2518        diff_fill_sha1_info(p->two);
2519
2520        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2521}
2522
2523void diff_setup(struct diff_options *options)
2524{
2525        memset(options, 0, sizeof(*options));
2526
2527        options->file = stdout;
2528
2529        options->line_termination = '\n';
2530        options->break_opt = -1;
2531        options->rename_limit = -1;
2532        options->dirstat_percent = 3;
2533        options->context = 3;
2534
2535        options->change = diff_change;
2536        options->add_remove = diff_addremove;
2537        if (diff_use_color_default > 0)
2538                DIFF_OPT_SET(options, COLOR_DIFF);
2539        options->detect_rename = diff_detect_rename_default;
2540
2541        if (!diff_mnemonic_prefix) {
2542                options->a_prefix = "a/";
2543                options->b_prefix = "b/";
2544        }
2545}
2546
2547int diff_setup_done(struct diff_options *options)
2548{
2549        int count = 0;
2550
2551        if (options->output_format & DIFF_FORMAT_NAME)
2552                count++;
2553        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2554                count++;
2555        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2556                count++;
2557        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2558                count++;
2559        if (count > 1)
2560                die("--name-only, --name-status, --check and -s are mutually exclusive");
2561
2562        /*
2563         * Most of the time we can say "there are changes"
2564         * only by checking if there are changed paths, but
2565         * --ignore-whitespace* options force us to look
2566         * inside contents.
2567         */
2568
2569        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2570            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2571            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2572                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2573        else
2574                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2575
2576        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2577                options->detect_rename = DIFF_DETECT_COPY;
2578
2579        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2580                options->prefix = NULL;
2581        if (options->prefix)
2582                options->prefix_length = strlen(options->prefix);
2583        else
2584                options->prefix_length = 0;
2585
2586        if (options->output_format & (DIFF_FORMAT_NAME |
2587                                      DIFF_FORMAT_NAME_STATUS |
2588                                      DIFF_FORMAT_CHECKDIFF |
2589                                      DIFF_FORMAT_NO_OUTPUT))
2590                options->output_format &= ~(DIFF_FORMAT_RAW |
2591                                            DIFF_FORMAT_NUMSTAT |
2592                                            DIFF_FORMAT_DIFFSTAT |
2593                                            DIFF_FORMAT_SHORTSTAT |
2594                                            DIFF_FORMAT_DIRSTAT |
2595                                            DIFF_FORMAT_SUMMARY |
2596                                            DIFF_FORMAT_PATCH);
2597
2598        /*
2599         * These cases always need recursive; we do not drop caller-supplied
2600         * recursive bits for other formats here.
2601         */
2602        if (options->output_format & (DIFF_FORMAT_PATCH |
2603                                      DIFF_FORMAT_NUMSTAT |
2604                                      DIFF_FORMAT_DIFFSTAT |
2605                                      DIFF_FORMAT_SHORTSTAT |
2606                                      DIFF_FORMAT_DIRSTAT |
2607                                      DIFF_FORMAT_SUMMARY |
2608                                      DIFF_FORMAT_CHECKDIFF))
2609                DIFF_OPT_SET(options, RECURSIVE);
2610        /*
2611         * Also pickaxe would not work very well if you do not say recursive
2612         */
2613        if (options->pickaxe)
2614                DIFF_OPT_SET(options, RECURSIVE);
2615        /*
2616         * When patches are generated, submodules diffed against the work tree
2617         * must be checked for dirtiness too so it can be shown in the output
2618         */
2619        if (options->output_format & DIFF_FORMAT_PATCH)
2620                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2621
2622        if (options->detect_rename && options->rename_limit < 0)
2623                options->rename_limit = diff_rename_limit_default;
2624        if (options->setup & DIFF_SETUP_USE_CACHE) {
2625                if (!active_cache)
2626                        /* read-cache does not die even when it fails
2627                         * so it is safe for us to do this here.  Also
2628                         * it does not smudge active_cache or active_nr
2629                         * when it fails, so we do not have to worry about
2630                         * cleaning it up ourselves either.
2631                         */
2632                        read_cache();
2633        }
2634        if (options->abbrev <= 0 || 40 < options->abbrev)
2635                options->abbrev = 40; /* full */
2636
2637        /*
2638         * It does not make sense to show the first hit we happened
2639         * to have found.  It does not make sense not to return with
2640         * exit code in such a case either.
2641         */
2642        if (DIFF_OPT_TST(options, QUICK)) {
2643                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2644                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2645        }
2646
2647        return 0;
2648}
2649
2650static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2651{
2652        char c, *eq;
2653        int len;
2654
2655        if (*arg != '-')
2656                return 0;
2657        c = *++arg;
2658        if (!c)
2659                return 0;
2660        if (c == arg_short) {
2661                c = *++arg;
2662                if (!c)
2663                        return 1;
2664                if (val && isdigit(c)) {
2665                        char *end;
2666                        int n = strtoul(arg, &end, 10);
2667                        if (*end)
2668                                return 0;
2669                        *val = n;
2670                        return 1;
2671                }
2672                return 0;
2673        }
2674        if (c != '-')
2675                return 0;
2676        arg++;
2677        eq = strchr(arg, '=');
2678        if (eq)
2679                len = eq - arg;
2680        else
2681                len = strlen(arg);
2682        if (!len || strncmp(arg, arg_long, len))
2683                return 0;
2684        if (eq) {
2685                int n;
2686                char *end;
2687                if (!isdigit(*++eq))
2688                        return 0;
2689                n = strtoul(eq, &end, 10);
2690                if (*end)
2691                        return 0;
2692                *val = n;
2693        }
2694        return 1;
2695}
2696
2697static int diff_scoreopt_parse(const char *opt);
2698
2699int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2700{
2701        const char *arg = av[0];
2702
2703        /* Output format options */
2704        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2705                options->output_format |= DIFF_FORMAT_PATCH;
2706        else if (opt_arg(arg, 'U', "unified", &options->context))
2707                options->output_format |= DIFF_FORMAT_PATCH;
2708        else if (!strcmp(arg, "--raw"))
2709                options->output_format |= DIFF_FORMAT_RAW;
2710        else if (!strcmp(arg, "--patch-with-raw"))
2711                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2712        else if (!strcmp(arg, "--numstat"))
2713                options->output_format |= DIFF_FORMAT_NUMSTAT;
2714        else if (!strcmp(arg, "--shortstat"))
2715                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2716        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2717                options->output_format |= DIFF_FORMAT_DIRSTAT;
2718        else if (!strcmp(arg, "--cumulative")) {
2719                options->output_format |= DIFF_FORMAT_DIRSTAT;
2720                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2721        } else if (opt_arg(arg, 0, "dirstat-by-file",
2722                           &options->dirstat_percent)) {
2723                options->output_format |= DIFF_FORMAT_DIRSTAT;
2724                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2725        }
2726        else if (!strcmp(arg, "--check"))
2727                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2728        else if (!strcmp(arg, "--summary"))
2729                options->output_format |= DIFF_FORMAT_SUMMARY;
2730        else if (!strcmp(arg, "--patch-with-stat"))
2731                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2732        else if (!strcmp(arg, "--name-only"))
2733                options->output_format |= DIFF_FORMAT_NAME;
2734        else if (!strcmp(arg, "--name-status"))
2735                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2736        else if (!strcmp(arg, "-s"))
2737                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2738        else if (!prefixcmp(arg, "--stat")) {
2739                char *end;
2740                int width = options->stat_width;
2741                int name_width = options->stat_name_width;
2742                arg += 6;
2743                end = (char *)arg;
2744
2745                switch (*arg) {
2746                case '-':
2747                        if (!prefixcmp(arg, "-width="))
2748                                width = strtoul(arg + 7, &end, 10);
2749                        else if (!prefixcmp(arg, "-name-width="))
2750                                name_width = strtoul(arg + 12, &end, 10);
2751                        break;
2752                case '=':
2753                        width = strtoul(arg+1, &end, 10);
2754                        if (*end == ',')
2755                                name_width = strtoul(end+1, &end, 10);
2756                }
2757
2758                /* Important! This checks all the error cases! */
2759                if (*end)
2760                        return 0;
2761                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2762                options->stat_name_width = name_width;
2763                options->stat_width = width;
2764        }
2765
2766        /* renames options */
2767        else if (!prefixcmp(arg, "-B")) {
2768                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2769                        return -1;
2770        }
2771        else if (!prefixcmp(arg, "-M")) {
2772                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2773                        return -1;
2774                options->detect_rename = DIFF_DETECT_RENAME;
2775        }
2776        else if (!prefixcmp(arg, "-C")) {
2777                if (options->detect_rename == DIFF_DETECT_COPY)
2778                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2779                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2780                        return -1;
2781                options->detect_rename = DIFF_DETECT_COPY;
2782        }
2783        else if (!strcmp(arg, "--no-renames"))
2784                options->detect_rename = 0;
2785        else if (!strcmp(arg, "--relative"))
2786                DIFF_OPT_SET(options, RELATIVE_NAME);
2787        else if (!prefixcmp(arg, "--relative=")) {
2788                DIFF_OPT_SET(options, RELATIVE_NAME);
2789                options->prefix = arg + 11;
2790        }
2791
2792        /* xdiff options */
2793        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2794                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2795        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2796                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2797        else if (!strcmp(arg, "--ignore-space-at-eol"))
2798                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2799        else if (!strcmp(arg, "--patience"))
2800                DIFF_XDL_SET(options, PATIENCE_DIFF);
2801
2802        /* flags options */
2803        else if (!strcmp(arg, "--binary")) {
2804                options->output_format |= DIFF_FORMAT_PATCH;
2805                DIFF_OPT_SET(options, BINARY);
2806        }
2807        else if (!strcmp(arg, "--full-index"))
2808                DIFF_OPT_SET(options, FULL_INDEX);
2809        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2810                DIFF_OPT_SET(options, TEXT);
2811        else if (!strcmp(arg, "-R"))
2812                DIFF_OPT_SET(options, REVERSE_DIFF);
2813        else if (!strcmp(arg, "--find-copies-harder"))
2814                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2815        else if (!strcmp(arg, "--follow"))
2816                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2817        else if (!strcmp(arg, "--color"))
2818                DIFF_OPT_SET(options, COLOR_DIFF);
2819        else if (!prefixcmp(arg, "--color=")) {
2820                int value = git_config_colorbool(NULL, arg+8, -1);
2821                if (value == 0)
2822                        DIFF_OPT_CLR(options, COLOR_DIFF);
2823                else if (value > 0)
2824                        DIFF_OPT_SET(options, COLOR_DIFF);
2825                else
2826                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
2827        }
2828        else if (!strcmp(arg, "--no-color"))
2829                DIFF_OPT_CLR(options, COLOR_DIFF);
2830        else if (!strcmp(arg, "--color-words")) {
2831                DIFF_OPT_SET(options, COLOR_DIFF);
2832                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2833        }
2834        else if (!prefixcmp(arg, "--color-words=")) {
2835                DIFF_OPT_SET(options, COLOR_DIFF);
2836                DIFF_OPT_SET(options, COLOR_DIFF_WORDS);
2837                options->word_regex = arg + 14;
2838        }
2839        else if (!strcmp(arg, "--exit-code"))
2840                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2841        else if (!strcmp(arg, "--quiet"))
2842                DIFF_OPT_SET(options, QUICK);
2843        else if (!strcmp(arg, "--ext-diff"))
2844                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2845        else if (!strcmp(arg, "--no-ext-diff"))
2846                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2847        else if (!strcmp(arg, "--textconv"))
2848                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2849        else if (!strcmp(arg, "--no-textconv"))
2850                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2851        else if (!strcmp(arg, "--ignore-submodules"))
2852                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2853        else if (!strcmp(arg, "--submodule"))
2854                DIFF_OPT_SET(options, SUBMODULE_LOG);
2855        else if (!prefixcmp(arg, "--submodule=")) {
2856                if (!strcmp(arg + 12, "log"))
2857                        DIFF_OPT_SET(options, SUBMODULE_LOG);
2858        }
2859
2860        /* misc options */
2861        else if (!strcmp(arg, "-z"))
2862                options->line_termination = 0;
2863        else if (!prefixcmp(arg, "-l"))
2864                options->rename_limit = strtoul(arg+2, NULL, 10);
2865        else if (!prefixcmp(arg, "-S"))
2866                options->pickaxe = arg + 2;
2867        else if (!strcmp(arg, "--pickaxe-all"))
2868                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2869        else if (!strcmp(arg, "--pickaxe-regex"))
2870                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2871        else if (!prefixcmp(arg, "-O"))
2872                options->orderfile = arg + 2;
2873        else if (!prefixcmp(arg, "--diff-filter="))
2874                options->filter = arg + 14;
2875        else if (!strcmp(arg, "--abbrev"))
2876                options->abbrev = DEFAULT_ABBREV;
2877        else if (!prefixcmp(arg, "--abbrev=")) {
2878                options->abbrev = strtoul(arg + 9, NULL, 10);
2879                if (options->abbrev < MINIMUM_ABBREV)
2880                        options->abbrev = MINIMUM_ABBREV;
2881                else if (40 < options->abbrev)
2882                        options->abbrev = 40;
2883        }
2884        else if (!prefixcmp(arg, "--src-prefix="))
2885                options->a_prefix = arg + 13;
2886        else if (!prefixcmp(arg, "--dst-prefix="))
2887                options->b_prefix = arg + 13;
2888        else if (!strcmp(arg, "--no-prefix"))
2889                options->a_prefix = options->b_prefix = "";
2890        else if (opt_arg(arg, '\0', "inter-hunk-context",
2891                         &options->interhunkcontext))
2892                ;
2893        else if (!prefixcmp(arg, "--output=")) {
2894                options->file = fopen(arg + strlen("--output="), "w");
2895                if (!options->file)
2896                        die_errno("Could not open '%s'", arg + strlen("--output="));
2897                options->close_file = 1;
2898        } else
2899                return 0;
2900        return 1;
2901}
2902
2903static int parse_num(const char **cp_p)
2904{
2905        unsigned long num, scale;
2906        int ch, dot;
2907        const char *cp = *cp_p;
2908
2909        num = 0;
2910        scale = 1;
2911        dot = 0;
2912        for (;;) {
2913                ch = *cp;
2914                if ( !dot && ch == '.' ) {
2915                        scale = 1;
2916                        dot = 1;
2917                } else if ( ch == '%' ) {
2918                        scale = dot ? scale*100 : 100;
2919                        cp++;   /* % is always at the end */
2920                        break;
2921                } else if ( ch >= '0' && ch <= '9' ) {
2922                        if ( scale < 100000 ) {
2923                                scale *= 10;
2924                                num = (num*10) + (ch-'0');
2925                        }
2926                } else {
2927                        break;
2928                }
2929                cp++;
2930        }
2931        *cp_p = cp;
2932
2933        /* user says num divided by scale and we say internally that
2934         * is MAX_SCORE * num / scale.
2935         */
2936        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2937}
2938
2939static int diff_scoreopt_parse(const char *opt)
2940{
2941        int opt1, opt2, cmd;
2942
2943        if (*opt++ != '-')
2944                return -1;
2945        cmd = *opt++;
2946        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2947                return -1; /* that is not a -M, -C nor -B option */
2948
2949        opt1 = parse_num(&opt);
2950        if (cmd != 'B')
2951                opt2 = 0;
2952        else {
2953                if (*opt == 0)
2954                        opt2 = 0;
2955                else if (*opt != '/')
2956                        return -1; /* we expect -B80/99 or -B80 */
2957                else {
2958                        opt++;
2959                        opt2 = parse_num(&opt);
2960                }
2961        }
2962        if (*opt != 0)
2963                return -1;
2964        return opt1 | (opt2 << 16);
2965}
2966
2967struct diff_queue_struct diff_queued_diff;
2968
2969void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2970{
2971        if (queue->alloc <= queue->nr) {
2972                queue->alloc = alloc_nr(queue->alloc);
2973                queue->queue = xrealloc(queue->queue,
2974                                        sizeof(dp) * queue->alloc);
2975        }
2976        queue->queue[queue->nr++] = dp;
2977}
2978
2979struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2980                                 struct diff_filespec *one,
2981                                 struct diff_filespec *two)
2982{
2983        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2984        dp->one = one;
2985        dp->two = two;
2986        if (queue)
2987                diff_q(queue, dp);
2988        return dp;
2989}
2990
2991void diff_free_filepair(struct diff_filepair *p)
2992{
2993        free_filespec(p->one);
2994        free_filespec(p->two);
2995        free(p);
2996}
2997
2998/* This is different from find_unique_abbrev() in that
2999 * it stuffs the result with dots for alignment.
3000 */
3001const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3002{
3003        int abblen;
3004        const char *abbrev;
3005        if (len == 40)
3006                return sha1_to_hex(sha1);
3007
3008        abbrev = find_unique_abbrev(sha1, len);
3009        abblen = strlen(abbrev);
3010        if (abblen < 37) {
3011                static char hex[41];
3012                if (len < abblen && abblen <= len + 2)
3013                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3014                else
3015                        sprintf(hex, "%s...", abbrev);
3016                return hex;
3017        }
3018        return sha1_to_hex(sha1);
3019}
3020
3021static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3022{
3023        int line_termination = opt->line_termination;
3024        int inter_name_termination = line_termination ? '\t' : '\0';
3025
3026        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3027                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3028                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3029                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3030        }
3031        if (p->score) {
3032                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3033                        inter_name_termination);
3034        } else {
3035                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3036        }
3037
3038        if (p->status == DIFF_STATUS_COPIED ||
3039            p->status == DIFF_STATUS_RENAMED) {
3040                const char *name_a, *name_b;
3041                name_a = p->one->path;
3042                name_b = p->two->path;
3043                strip_prefix(opt->prefix_length, &name_a, &name_b);
3044                write_name_quoted(name_a, opt->file, inter_name_termination);
3045                write_name_quoted(name_b, opt->file, line_termination);
3046        } else {
3047                const char *name_a, *name_b;
3048                name_a = p->one->mode ? p->one->path : p->two->path;
3049                name_b = NULL;
3050                strip_prefix(opt->prefix_length, &name_a, &name_b);
3051                write_name_quoted(name_a, opt->file, line_termination);
3052        }
3053}
3054
3055int diff_unmodified_pair(struct diff_filepair *p)
3056{
3057        /* This function is written stricter than necessary to support
3058         * the currently implemented transformers, but the idea is to
3059         * let transformers to produce diff_filepairs any way they want,
3060         * and filter and clean them up here before producing the output.
3061         */
3062        struct diff_filespec *one = p->one, *two = p->two;
3063
3064        if (DIFF_PAIR_UNMERGED(p))
3065                return 0; /* unmerged is interesting */
3066
3067        /* deletion, addition, mode or type change
3068         * and rename are all interesting.
3069         */
3070        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3071            DIFF_PAIR_MODE_CHANGED(p) ||
3072            strcmp(one->path, two->path))
3073                return 0;
3074
3075        /* both are valid and point at the same path.  that is, we are
3076         * dealing with a change.
3077         */
3078        if (one->sha1_valid && two->sha1_valid &&
3079            !hashcmp(one->sha1, two->sha1) &&
3080            !one->dirty_submodule && !two->dirty_submodule)
3081                return 1; /* no change */
3082        if (!one->sha1_valid && !two->sha1_valid)
3083                return 1; /* both look at the same file on the filesystem. */
3084        return 0;
3085}
3086
3087static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3088{
3089        if (diff_unmodified_pair(p))
3090                return;
3091
3092        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3093            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3094                return; /* no tree diffs in patch format */
3095
3096        run_diff(p, o);
3097}
3098
3099static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3100                            struct diffstat_t *diffstat)
3101{
3102        if (diff_unmodified_pair(p))
3103                return;
3104
3105        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3106            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3107                return; /* no tree diffs in patch format */
3108
3109        run_diffstat(p, o, diffstat);
3110}
3111
3112static void diff_flush_checkdiff(struct diff_filepair *p,
3113                struct diff_options *o)
3114{
3115        if (diff_unmodified_pair(p))
3116                return;
3117
3118        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3119            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3120                return; /* no tree diffs in patch format */
3121
3122        run_checkdiff(p, o);
3123}
3124
3125int diff_queue_is_empty(void)
3126{
3127        struct diff_queue_struct *q = &diff_queued_diff;
3128        int i;
3129        for (i = 0; i < q->nr; i++)
3130                if (!diff_unmodified_pair(q->queue[i]))
3131                        return 0;
3132        return 1;
3133}
3134
3135#if DIFF_DEBUG
3136void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3137{
3138        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3139                x, one ? one : "",
3140                s->path,
3141                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3142                s->mode,
3143                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3144        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3145                x, one ? one : "",
3146                s->size, s->xfrm_flags);
3147}
3148
3149void diff_debug_filepair(const struct diff_filepair *p, int i)
3150{
3151        diff_debug_filespec(p->one, i, "one");
3152        diff_debug_filespec(p->two, i, "two");
3153        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3154                p->score, p->status ? p->status : '?',
3155                p->one->rename_used, p->broken_pair);
3156}
3157
3158void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3159{
3160        int i;
3161        if (msg)
3162                fprintf(stderr, "%s\n", msg);
3163        fprintf(stderr, "q->nr = %d\n", q->nr);
3164        for (i = 0; i < q->nr; i++) {
3165                struct diff_filepair *p = q->queue[i];
3166                diff_debug_filepair(p, i);
3167        }
3168}
3169#endif
3170
3171static void diff_resolve_rename_copy(void)
3172{
3173        int i;
3174        struct diff_filepair *p;
3175        struct diff_queue_struct *q = &diff_queued_diff;
3176
3177        diff_debug_queue("resolve-rename-copy", q);
3178
3179        for (i = 0; i < q->nr; i++) {
3180                p = q->queue[i];
3181                p->status = 0; /* undecided */
3182                if (DIFF_PAIR_UNMERGED(p))
3183                        p->status = DIFF_STATUS_UNMERGED;
3184                else if (!DIFF_FILE_VALID(p->one))
3185                        p->status = DIFF_STATUS_ADDED;
3186                else if (!DIFF_FILE_VALID(p->two))
3187                        p->status = DIFF_STATUS_DELETED;
3188                else if (DIFF_PAIR_TYPE_CHANGED(p))
3189                        p->status = DIFF_STATUS_TYPE_CHANGED;
3190
3191                /* from this point on, we are dealing with a pair
3192                 * whose both sides are valid and of the same type, i.e.
3193                 * either in-place edit or rename/copy edit.
3194                 */
3195                else if (DIFF_PAIR_RENAME(p)) {
3196                        /*
3197                         * A rename might have re-connected a broken
3198                         * pair up, causing the pathnames to be the
3199                         * same again. If so, that's not a rename at
3200                         * all, just a modification..
3201                         *
3202                         * Otherwise, see if this source was used for
3203                         * multiple renames, in which case we decrement
3204                         * the count, and call it a copy.
3205                         */
3206                        if (!strcmp(p->one->path, p->two->path))
3207                                p->status = DIFF_STATUS_MODIFIED;
3208                        else if (--p->one->rename_used > 0)
3209                                p->status = DIFF_STATUS_COPIED;
3210                        else
3211                                p->status = DIFF_STATUS_RENAMED;
3212                }
3213                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3214                         p->one->mode != p->two->mode ||
3215                         p->one->dirty_submodule ||
3216                         p->two->dirty_submodule ||
3217                         is_null_sha1(p->one->sha1))
3218                        p->status = DIFF_STATUS_MODIFIED;
3219                else {
3220                        /* This is a "no-change" entry and should not
3221                         * happen anymore, but prepare for broken callers.
3222                         */
3223                        error("feeding unmodified %s to diffcore",
3224                              p->one->path);
3225                        p->status = DIFF_STATUS_UNKNOWN;
3226                }
3227        }
3228        diff_debug_queue("resolve-rename-copy done", q);
3229}
3230
3231static int check_pair_status(struct diff_filepair *p)
3232{
3233        switch (p->status) {
3234        case DIFF_STATUS_UNKNOWN:
3235                return 0;
3236        case 0:
3237                die("internal error in diff-resolve-rename-copy");
3238        default:
3239                return 1;
3240        }
3241}
3242
3243static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3244{
3245        int fmt = opt->output_format;
3246
3247        if (fmt & DIFF_FORMAT_CHECKDIFF)
3248                diff_flush_checkdiff(p, opt);
3249        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3250                diff_flush_raw(p, opt);
3251        else if (fmt & DIFF_FORMAT_NAME) {
3252                const char *name_a, *name_b;
3253                name_a = p->two->path;
3254                name_b = NULL;
3255                strip_prefix(opt->prefix_length, &name_a, &name_b);
3256                write_name_quoted(name_a, opt->file, opt->line_termination);
3257        }
3258}
3259
3260static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3261{
3262        if (fs->mode)
3263                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3264        else
3265                fprintf(file, " %s ", newdelete);
3266        write_name_quoted(fs->path, file, '\n');
3267}
3268
3269
3270static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
3271{
3272        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3273                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
3274                        show_name ? ' ' : '\n');
3275                if (show_name) {
3276                        write_name_quoted(p->two->path, file, '\n');
3277                }
3278        }
3279}
3280
3281static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
3282{
3283        char *names = pprint_rename(p->one->path, p->two->path);
3284
3285        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3286        free(names);
3287        show_mode_change(file, p, 0);
3288}
3289
3290static void diff_summary(FILE *file, struct diff_filepair *p)
3291{
3292        switch(p->status) {
3293        case DIFF_STATUS_DELETED:
3294                show_file_mode_name(file, "delete", p->one);
3295                break;
3296        case DIFF_STATUS_ADDED:
3297                show_file_mode_name(file, "create", p->two);
3298                break;
3299        case DIFF_STATUS_COPIED:
3300                show_rename_copy(file, "copy", p);
3301                break;
3302        case DIFF_STATUS_RENAMED:
3303                show_rename_copy(file, "rename", p);
3304                break;
3305        default:
3306                if (p->score) {
3307                        fputs(" rewrite ", file);
3308                        write_name_quoted(p->two->path, file, ' ');
3309                        fprintf(file, "(%d%%)\n", similarity_index(p));
3310                }
3311                show_mode_change(file, p, !p->score);
3312                break;
3313        }
3314}
3315
3316struct patch_id_t {
3317        git_SHA_CTX *ctx;
3318        int patchlen;
3319};
3320
3321static int remove_space(char *line, int len)
3322{
3323        int i;
3324        char *dst = line;
3325        unsigned char c;
3326
3327        for (i = 0; i < len; i++)
3328                if (!isspace((c = line[i])))
3329                        *dst++ = c;
3330
3331        return dst - line;
3332}
3333
3334static void patch_id_consume(void *priv, char *line, unsigned long len)
3335{
3336        struct patch_id_t *data = priv;
3337        int new_len;
3338
3339        /* Ignore line numbers when computing the SHA1 of the patch */
3340        if (!prefixcmp(line, "@@ -"))
3341                return;
3342
3343        new_len = remove_space(line, len);
3344
3345        git_SHA1_Update(data->ctx, line, new_len);
3346        data->patchlen += new_len;
3347}
3348
3349/* returns 0 upon success, and writes result into sha1 */
3350static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3351{
3352        struct diff_queue_struct *q = &diff_queued_diff;
3353        int i;
3354        git_SHA_CTX ctx;
3355        struct patch_id_t data;
3356        char buffer[PATH_MAX * 4 + 20];
3357
3358        git_SHA1_Init(&ctx);
3359        memset(&data, 0, sizeof(struct patch_id_t));
3360        data.ctx = &ctx;
3361
3362        for (i = 0; i < q->nr; i++) {
3363                xpparam_t xpp;
3364                xdemitconf_t xecfg;
3365                mmfile_t mf1, mf2;
3366                struct diff_filepair *p = q->queue[i];
3367                int len1, len2;
3368
3369                memset(&xpp, 0, sizeof(xpp));
3370                memset(&xecfg, 0, sizeof(xecfg));
3371                if (p->status == 0)
3372                        return error("internal diff status error");
3373                if (p->status == DIFF_STATUS_UNKNOWN)
3374                        continue;
3375                if (diff_unmodified_pair(p))
3376                        continue;
3377                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3378                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3379                        continue;
3380                if (DIFF_PAIR_UNMERGED(p))
3381                        continue;
3382
3383                diff_fill_sha1_info(p->one);
3384                diff_fill_sha1_info(p->two);
3385                if (fill_mmfile(&mf1, p->one) < 0 ||
3386                                fill_mmfile(&mf2, p->two) < 0)
3387                        return error("unable to read files to diff");
3388
3389                len1 = remove_space(p->one->path, strlen(p->one->path));
3390                len2 = remove_space(p->two->path, strlen(p->two->path));
3391                if (p->one->mode == 0)
3392                        len1 = snprintf(buffer, sizeof(buffer),
3393                                        "diff--gita/%.*sb/%.*s"
3394                                        "newfilemode%06o"
3395                                        "---/dev/null"
3396                                        "+++b/%.*s",
3397                                        len1, p->one->path,
3398                                        len2, p->two->path,
3399                                        p->two->mode,
3400                                        len2, p->two->path);
3401                else if (p->two->mode == 0)
3402                        len1 = snprintf(buffer, sizeof(buffer),
3403                                        "diff--gita/%.*sb/%.*s"
3404                                        "deletedfilemode%06o"
3405                                        "---a/%.*s"
3406                                        "+++/dev/null",
3407                                        len1, p->one->path,
3408                                        len2, p->two->path,
3409                                        p->one->mode,
3410                                        len1, p->one->path);
3411                else
3412                        len1 = snprintf(buffer, sizeof(buffer),
3413                                        "diff--gita/%.*sb/%.*s"
3414                                        "---a/%.*s"
3415                                        "+++b/%.*s",
3416                                        len1, p->one->path,
3417                                        len2, p->two->path,
3418                                        len1, p->one->path,
3419                                        len2, p->two->path);
3420                git_SHA1_Update(&ctx, buffer, len1);
3421
3422                xpp.flags = XDF_NEED_MINIMAL;
3423                xecfg.ctxlen = 3;
3424                xecfg.flags = XDL_EMIT_FUNCNAMES;
3425                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3426                              &xpp, &xecfg);
3427        }
3428
3429        git_SHA1_Final(sha1, &ctx);
3430        return 0;
3431}
3432
3433int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3434{
3435        struct diff_queue_struct *q = &diff_queued_diff;
3436        int i;
3437        int result = diff_get_patch_id(options, sha1);
3438
3439        for (i = 0; i < q->nr; i++)
3440                diff_free_filepair(q->queue[i]);
3441
3442        free(q->queue);
3443        q->queue = NULL;
3444        q->nr = q->alloc = 0;
3445
3446        return result;
3447}
3448
3449static int is_summary_empty(const struct diff_queue_struct *q)
3450{
3451        int i;
3452
3453        for (i = 0; i < q->nr; i++) {
3454                const struct diff_filepair *p = q->queue[i];
3455
3456                switch (p->status) {
3457                case DIFF_STATUS_DELETED:
3458                case DIFF_STATUS_ADDED:
3459                case DIFF_STATUS_COPIED:
3460                case DIFF_STATUS_RENAMED:
3461                        return 0;
3462                default:
3463                        if (p->score)
3464                                return 0;
3465                        if (p->one->mode && p->two->mode &&
3466                            p->one->mode != p->two->mode)
3467                                return 0;
3468                        break;
3469                }
3470        }
3471        return 1;
3472}
3473
3474void diff_flush(struct diff_options *options)
3475{
3476        struct diff_queue_struct *q = &diff_queued_diff;
3477        int i, output_format = options->output_format;
3478        int separator = 0;
3479
3480        /*
3481         * Order: raw, stat, summary, patch
3482         * or:    name/name-status/checkdiff (other bits clear)
3483         */
3484        if (!q->nr)
3485                goto free_queue;
3486
3487        if (output_format & (DIFF_FORMAT_RAW |
3488                             DIFF_FORMAT_NAME |
3489                             DIFF_FORMAT_NAME_STATUS |
3490                             DIFF_FORMAT_CHECKDIFF)) {
3491                for (i = 0; i < q->nr; i++) {
3492                        struct diff_filepair *p = q->queue[i];
3493                        if (check_pair_status(p))
3494                                flush_one_pair(p, options);
3495                }
3496                separator++;
3497        }
3498
3499        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3500                struct diffstat_t diffstat;
3501
3502                memset(&diffstat, 0, sizeof(struct diffstat_t));
3503                for (i = 0; i < q->nr; i++) {
3504                        struct diff_filepair *p = q->queue[i];
3505                        if (check_pair_status(p))
3506                                diff_flush_stat(p, options, &diffstat);
3507                }
3508                if (output_format & DIFF_FORMAT_NUMSTAT)
3509                        show_numstat(&diffstat, options);
3510                if (output_format & DIFF_FORMAT_DIFFSTAT)
3511                        show_stats(&diffstat, options);
3512                if (output_format & DIFF_FORMAT_SHORTSTAT)
3513                        show_shortstats(&diffstat, options);
3514                free_diffstat_info(&diffstat);
3515                separator++;
3516        }
3517        if (output_format & DIFF_FORMAT_DIRSTAT)
3518                show_dirstat(options);
3519
3520        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3521                for (i = 0; i < q->nr; i++)
3522                        diff_summary(options->file, q->queue[i]);
3523                separator++;
3524        }
3525
3526        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3527            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3528            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3529                /*
3530                 * run diff_flush_patch for the exit status. setting
3531                 * options->file to /dev/null should be safe, becaue we
3532                 * aren't supposed to produce any output anyway.
3533                 */
3534                if (options->close_file)
3535                        fclose(options->file);
3536                options->file = fopen("/dev/null", "w");
3537                if (!options->file)
3538                        die_errno("Could not open /dev/null");
3539                options->close_file = 1;
3540                for (i = 0; i < q->nr; i++) {
3541                        struct diff_filepair *p = q->queue[i];
3542                        if (check_pair_status(p))
3543                                diff_flush_patch(p, options);
3544                        if (options->found_changes)
3545                                break;
3546                }
3547        }
3548
3549        if (output_format & DIFF_FORMAT_PATCH) {
3550                if (separator) {
3551                        putc(options->line_termination, options->file);
3552                        if (options->stat_sep) {
3553                                /* attach patch instead of inline */
3554                                fputs(options->stat_sep, options->file);
3555                        }
3556                }
3557
3558                for (i = 0; i < q->nr; i++) {
3559                        struct diff_filepair *p = q->queue[i];
3560                        if (check_pair_status(p))
3561                                diff_flush_patch(p, options);
3562                }
3563        }
3564
3565        if (output_format & DIFF_FORMAT_CALLBACK)
3566                options->format_callback(q, options, options->format_callback_data);
3567
3568        for (i = 0; i < q->nr; i++)
3569                diff_free_filepair(q->queue[i]);
3570free_queue:
3571        free(q->queue);
3572        q->queue = NULL;
3573        q->nr = q->alloc = 0;
3574        if (options->close_file)
3575                fclose(options->file);
3576
3577        /*
3578         * Report the content-level differences with HAS_CHANGES;
3579         * diff_addremove/diff_change does not set the bit when
3580         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3581         */
3582        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3583                if (options->found_changes)
3584                        DIFF_OPT_SET(options, HAS_CHANGES);
3585                else
3586                        DIFF_OPT_CLR(options, HAS_CHANGES);
3587        }
3588}
3589
3590static void diffcore_apply_filter(const char *filter)
3591{
3592        int i;
3593        struct diff_queue_struct *q = &diff_queued_diff;
3594        struct diff_queue_struct outq;
3595        outq.queue = NULL;
3596        outq.nr = outq.alloc = 0;
3597
3598        if (!filter)
3599                return;
3600
3601        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3602                int found;
3603                for (i = found = 0; !found && i < q->nr; i++) {
3604                        struct diff_filepair *p = q->queue[i];
3605                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3606                             ((p->score &&
3607                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3608                              (!p->score &&
3609                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3610                            ((p->status != DIFF_STATUS_MODIFIED) &&
3611                             strchr(filter, p->status)))
3612                                found++;
3613                }
3614                if (found)
3615                        return;
3616
3617                /* otherwise we will clear the whole queue
3618                 * by copying the empty outq at the end of this
3619                 * function, but first clear the current entries
3620                 * in the queue.
3621                 */
3622                for (i = 0; i < q->nr; i++)
3623                        diff_free_filepair(q->queue[i]);
3624        }
3625        else {
3626                /* Only the matching ones */
3627                for (i = 0; i < q->nr; i++) {
3628                        struct diff_filepair *p = q->queue[i];
3629
3630                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3631                             ((p->score &&
3632                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3633                              (!p->score &&
3634                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3635                            ((p->status != DIFF_STATUS_MODIFIED) &&
3636                             strchr(filter, p->status)))
3637                                diff_q(&outq, p);
3638                        else
3639                                diff_free_filepair(p);
3640                }
3641        }
3642        free(q->queue);
3643        *q = outq;
3644}
3645
3646/* Check whether two filespecs with the same mode and size are identical */
3647static int diff_filespec_is_identical(struct diff_filespec *one,
3648                                      struct diff_filespec *two)
3649{
3650        if (S_ISGITLINK(one->mode))
3651                return 0;
3652        if (diff_populate_filespec(one, 0))
3653                return 0;
3654        if (diff_populate_filespec(two, 0))
3655                return 0;
3656        return !memcmp(one->data, two->data, one->size);
3657}
3658
3659static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3660{
3661        int i;
3662        struct diff_queue_struct *q = &diff_queued_diff;
3663        struct diff_queue_struct outq;
3664        outq.queue = NULL;
3665        outq.nr = outq.alloc = 0;
3666
3667        for (i = 0; i < q->nr; i++) {
3668                struct diff_filepair *p = q->queue[i];
3669
3670                /*
3671                 * 1. Entries that come from stat info dirtiness
3672                 *    always have both sides (iow, not create/delete),
3673                 *    one side of the object name is unknown, with
3674                 *    the same mode and size.  Keep the ones that
3675                 *    do not match these criteria.  They have real
3676                 *    differences.
3677                 *
3678                 * 2. At this point, the file is known to be modified,
3679                 *    with the same mode and size, and the object
3680                 *    name of one side is unknown.  Need to inspect
3681                 *    the identical contents.
3682                 */
3683                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3684                    !DIFF_FILE_VALID(p->two) ||
3685                    (p->one->sha1_valid && p->two->sha1_valid) ||
3686                    (p->one->mode != p->two->mode) ||
3687                    diff_populate_filespec(p->one, 1) ||
3688                    diff_populate_filespec(p->two, 1) ||
3689                    (p->one->size != p->two->size) ||
3690                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3691                        diff_q(&outq, p);
3692                else {
3693                        /*
3694                         * The caller can subtract 1 from skip_stat_unmatch
3695                         * to determine how many paths were dirty only
3696                         * due to stat info mismatch.
3697                         */
3698                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3699                                diffopt->skip_stat_unmatch++;
3700                        diff_free_filepair(p);
3701                }
3702        }
3703        free(q->queue);
3704        *q = outq;
3705}
3706
3707static int diffnamecmp(const void *a_, const void *b_)
3708{
3709        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3710        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3711        const char *name_a, *name_b;
3712
3713        name_a = a->one ? a->one->path : a->two->path;
3714        name_b = b->one ? b->one->path : b->two->path;
3715        return strcmp(name_a, name_b);
3716}
3717
3718void diffcore_fix_diff_index(struct diff_options *options)
3719{
3720        struct diff_queue_struct *q = &diff_queued_diff;
3721        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3722}
3723
3724void diffcore_std(struct diff_options *options)
3725{
3726        if (options->skip_stat_unmatch)
3727                diffcore_skip_stat_unmatch(options);
3728        if (options->break_opt != -1)
3729                diffcore_break(options->break_opt);
3730        if (options->detect_rename)
3731                diffcore_rename(options);
3732        if (options->break_opt != -1)
3733                diffcore_merge_broken();
3734        if (options->pickaxe)
3735                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3736        if (options->orderfile)
3737                diffcore_order(options->orderfile);
3738        diff_resolve_rename_copy();
3739        diffcore_apply_filter(options->filter);
3740
3741        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3742                DIFF_OPT_SET(options, HAS_CHANGES);
3743        else
3744                DIFF_OPT_CLR(options, HAS_CHANGES);
3745}
3746
3747int diff_result_code(struct diff_options *opt, int status)
3748{
3749        int result = 0;
3750        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3751            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3752                return status;
3753        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3754            DIFF_OPT_TST(opt, HAS_CHANGES))
3755                result |= 01;
3756        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3757            DIFF_OPT_TST(opt, CHECK_FAILED))
3758                result |= 02;
3759        return result;
3760}
3761
3762void diff_addremove(struct diff_options *options,
3763                    int addremove, unsigned mode,
3764                    const unsigned char *sha1,
3765                    const char *concatpath, unsigned dirty_submodule)
3766{
3767        struct diff_filespec *one, *two;
3768
3769        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3770                return;
3771
3772        /* This may look odd, but it is a preparation for
3773         * feeding "there are unchanged files which should
3774         * not produce diffs, but when you are doing copy
3775         * detection you would need them, so here they are"
3776         * entries to the diff-core.  They will be prefixed
3777         * with something like '=' or '*' (I haven't decided
3778         * which but should not make any difference).
3779         * Feeding the same new and old to diff_change()
3780         * also has the same effect.
3781         * Before the final output happens, they are pruned after
3782         * merged into rename/copy pairs as appropriate.
3783         */
3784        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3785                addremove = (addremove == '+' ? '-' :
3786                             addremove == '-' ? '+' : addremove);
3787
3788        if (options->prefix &&
3789            strncmp(concatpath, options->prefix, options->prefix_length))
3790                return;
3791
3792        one = alloc_filespec(concatpath);
3793        two = alloc_filespec(concatpath);
3794
3795        if (addremove != '+')
3796                fill_filespec(one, sha1, mode);
3797        if (addremove != '-') {
3798                fill_filespec(two, sha1, mode);
3799                two->dirty_submodule = dirty_submodule;
3800        }
3801
3802        diff_queue(&diff_queued_diff, one, two);
3803        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3804                DIFF_OPT_SET(options, HAS_CHANGES);
3805}
3806
3807void diff_change(struct diff_options *options,
3808                 unsigned old_mode, unsigned new_mode,
3809                 const unsigned char *old_sha1,
3810                 const unsigned char *new_sha1,
3811                 const char *concatpath,
3812                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
3813{
3814        struct diff_filespec *one, *two;
3815
3816        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3817                        && S_ISGITLINK(new_mode))
3818                return;
3819
3820        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3821                unsigned tmp;
3822                const unsigned char *tmp_c;
3823                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3824                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3825                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
3826                        new_dirty_submodule = tmp;
3827        }
3828
3829        if (options->prefix &&
3830            strncmp(concatpath, options->prefix, options->prefix_length))
3831                return;
3832
3833        one = alloc_filespec(concatpath);
3834        two = alloc_filespec(concatpath);
3835        fill_filespec(one, old_sha1, old_mode);
3836        fill_filespec(two, new_sha1, new_mode);
3837        one->dirty_submodule = old_dirty_submodule;
3838        two->dirty_submodule = new_dirty_submodule;
3839
3840        diff_queue(&diff_queued_diff, one, two);
3841        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3842                DIFF_OPT_SET(options, HAS_CHANGES);
3843}
3844
3845void diff_unmerge(struct diff_options *options,
3846                  const char *path,
3847                  unsigned mode, const unsigned char *sha1)
3848{
3849        struct diff_filespec *one, *two;
3850
3851        if (options->prefix &&
3852            strncmp(path, options->prefix, options->prefix_length))
3853                return;
3854
3855        one = alloc_filespec(path);
3856        two = alloc_filespec(path);
3857        fill_filespec(one, sha1, mode);
3858        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3859}
3860
3861static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3862                size_t *outsize)
3863{
3864        struct diff_tempfile *temp;
3865        const char *argv[3];
3866        const char **arg = argv;
3867        struct child_process child;
3868        struct strbuf buf = STRBUF_INIT;
3869        int err = 0;
3870
3871        temp = prepare_temp_file(spec->path, spec);
3872        *arg++ = pgm;
3873        *arg++ = temp->name;
3874        *arg = NULL;
3875
3876        memset(&child, 0, sizeof(child));
3877        child.use_shell = 1;
3878        child.argv = argv;
3879        child.out = -1;
3880        if (start_command(&child)) {
3881                remove_tempfile();
3882                return NULL;
3883        }
3884
3885        if (strbuf_read(&buf, child.out, 0) < 0)
3886                err = error("error reading from textconv command '%s'", pgm);
3887        close(child.out);
3888
3889        if (finish_command(&child) || err) {
3890                strbuf_release(&buf);
3891                remove_tempfile();
3892                return NULL;
3893        }
3894        remove_tempfile();
3895
3896        return strbuf_detach(&buf, outsize);
3897}
3898
3899static size_t fill_textconv(struct userdiff_driver *driver,
3900                            struct diff_filespec *df,
3901                            char **outbuf)
3902{
3903        size_t size;
3904
3905        if (!driver || !driver->textconv) {
3906                if (!DIFF_FILE_VALID(df)) {
3907                        *outbuf = "";
3908                        return 0;
3909                }
3910                if (diff_populate_filespec(df, 0))
3911                        die("unable to read files to diff");
3912                *outbuf = df->data;
3913                return df->size;
3914        }
3915
3916        if (driver->textconv_cache) {
3917                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
3918                                          &size);
3919                if (*outbuf)
3920                        return size;
3921        }
3922
3923        *outbuf = run_textconv(driver->textconv, df, &size);
3924        if (!*outbuf)
3925                die("unable to read files to diff");
3926
3927        if (driver->textconv_cache) {
3928                /* ignore errors, as we might be in a readonly repository */
3929                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
3930                                size);
3931                /*
3932                 * we could save up changes and flush them all at the end,
3933                 * but we would need an extra call after all diffing is done.
3934                 * Since generating a cache entry is the slow path anyway,
3935                 * this extra overhead probably isn't a big deal.
3936                 */
3937                notes_cache_write(driver->textconv_cache);
3938        }
3939
3940        return size;
3941}